So I am 24 years old, and I've never had sex. I also don't drink. I don't smoke. I don't do drugs, and I don't drink coffee. I'm a Mormon. And I've lived in New York City for six years as a Mormon, and it is hard to be a Mormon here if you don't drink or if you don't do drugs, but it is especially hard to live in New York City if you don't have sex. Because I'm young and I wanna have relationships, and I wanna play too and, like, date and stuff. But unfortunately, because I don't have sex, the longest relationship I've ever been able to sustain is four weeks… and that was only because for two of them he was out of town.

There's this huge part of me that wants to be considered sexy. But if you're not selling sex, you really shouldn't advertise, and so I don't really ever get to come across as sexy. But one time I was at this vintage boutique, and I came across this 1940s slip. It was dark navy blue – lacy at the top and then silk – and it was the sexiest thing I'd ever seen. I tried it on, and I looked in the mirror, and I thought, Oh my gosh! I am sexy! Wow! Who knew I could be sexy? And so I bought it. I took it home, and I put it in a drawer, and no guy has ever seen me in it. But occasionally, late at night, I'll try it on and look in the mirror and think, I'm sexy!

And I know that Mormons are notorious for saying no to things, and you would think as a person who says no to a lot of things, I wouldn't be any fun. But while I say no to some things, I try to say yes to everything else, which makes me a really enjoyable person. I learned the power of saying yes when I was going to NYU. They used to have these career fairs, and I was a drama student, so they wouldn't even set up booths for us. But for all the business school students, they had tons and tons of booths with the coolest trinkets they would give away. And I discovered that if I said yes to all the questions they asked, I could get presents. They would ask, "Are you a Stern student?" "Yes." "Are you interested in a job at Morgan Stanley Dean Witter?" "Yes." And if I answered yes enough, I would get a cool triangle highlighter with three different colours. And I know that technically that's lying, and Mormons aren't supposed to lie by any means, but I figure I do everything else right so I can do that.

And then another time I was walking by the Javits Center and someone said, "Are you looking for the paper convention?" And I immediately was like, "Yes!" I walked in and there were all these booths, and I just said yes to everything people asked me, and I left with a bag full of amazing stationery. I thought, This is awesome! It all led up to the mother of all conventions. I had some friends in town at the Marriott, and we had breakfast. I glanced under the table and saw a badge, and it said, "Bob Barnett, 7-Eleven Convention." And I was like, "YES!" So I put the badge on, and we went down to this banquet hall, and they were celebrating 75 years of 7-Eleven. So I start mingling with people. I'm making friends, taking free samples. And I end up meeting the woman who's running the whole convention. And I was like, "I go to conventions all the time, and this is so well organised." And she said, "Did you need tickets for today's events?" And I said, "Yes." And so she gave me four tickets to Madame Tussauds, four tickets on a bus tour, four tickets to Radio City Music Hall, and then she said, "Will I be seeing you on tonight's cruise?" And I said, "Yes, but, you know, I sent all that stuff in, and they never mailed me anything back." And she was like, "What?!" And she ran off and came back with four tickets worth $150 each on a dinner cruise around Manhattan. So that night I got all dressed up, and me and my three friends went on this cruise.

It was 1,500 7-Eleven employees and us. And we start mingling. We dance. We get going in karaoke. And then they serve this four-course meal. And at the end of dinner my friend turns to me, and he says, "Elna, I dare you to make a toast." I don't even drink, so I've never made a toast before, but I've seen movies, so I took a knife, and I was, like, tink-tink-tink on my glass. Everybody shut up, and I said, "I'd like to make a toast to 7-Eleven for redefining convenience." And they cheered. And the thing that I love so much about saying yes is that where you start at the beginning of the day and where you end up can be two totally different places based on all the things that you say yes to. But then there's this other side of my life, which is that I do say no to a lot of things. And with sex, the thing I've learned is it's one thing to say no to having sex with someone you've dated for two weeks. It's actually pretty easy because for me that would be kinda slutty to just say yes after two weeks.

But it's a whole other experience to say no to having sex with someone when you feel like you're in love. I met my yes counterpart a year ago, and his name was Nick. And when I met him, immediately I was like, "You!" And he was like, "You!" And we were like, "YESSSS!" Our first date was amazing. We were walking by a movie set, and we decided to sneak on and pretend we were extras. And so we were extras in the back of all these scenes, and we ended up in the makeup department. And they asked us what we needed, and at the same time we both said, "Black eyes!" So they gave us these huge black eyes, and we spent the rest of the day going around New York City with black eyes. We had so much fun. We just kept going on adventures. And we were dating.

I didn't tell him I was Mormon, because I thought, You know what? In addition to being Mormon, I am a lot of other things. But I really, truthfully didn't wanna tell him I was Mormon because I wanted to get to date him, and I knew that it probably wouldn't work out if he knew I was Mormon. And so as casually as you can bring that up, a couple of weeks into dating him I said, "Oh, by the way… I'm Mormon." And he was like, "Oh, um… I'm an atheist. Can you be with an atheist?" And I was like, "Yes. Can you be with a Mormon?" And he said, "Yes." So we kept dating. And we kept going on adventures, and it was really, really wonderful.

But then there were these grander things than we were that kept interfering, as much as we tried to ignore them. And I remember one of the bigger ones was when I found out he didn't believe people had souls. I was like, "What? What!?!? Doesn't everyone believe that? I mean, religious or not, doesn't everyone believe people have souls?"

And he said, "No. I don't believe people have souls." I grabbed him by the shoulders, and I looked him in the eyes, and he was like, "What are you doing?" I said, "I'm looking at your soul. I can see it. I can hear it. I know it's there." And he was like, "Really? And what does my soul have to say?" And I listened really close and said, "It says… 'Fuck you. I've been inside you for 29 years, and you've been ignoring me the entire time. Argh!'"

So we kept dating, even though at this point I realised my soul mate didn't actually believe in souls. But I was willing to be OK with that. And then the sex thing came up, and he asked, "Are we gonna have sex?" And I said, "No." And then he did that thing where, like, he started to pull away. And I could tell he was starting to phase me out. It's so interesting because every girl knows when a guy starts to phase her out, even if it's just a coincidence that he didn't pick up his phone. You feel it and you know. And so I started thinking, Why would he wanna phase me out? It's because I'm Mormon and it's because I won't have sex. And then I started thinking, What if he's the love of my life, and I end up marrying a Mormon guy that I like OK, and I spend the rest of my life regretting this decision? What if he's right, and what if God doesn't exist, and then I'm making this sacrifice for this totally imaginary reason.

Elna Baker: 'I started thinking, What if he's the love of my life, and I end up marrying a Mormon guy that I like OK, and I spend the rest of my life regretting this decision?' Photograph: Rebecca Aldler

And then I started thinking about sex, and how when you're in love sex is totally different. It almost feels like a natural progression of things. And I thought, You know, maybe I could have sex. And then we went out again, and I sensed it was one of the last times we would get to go out with each other. We were supposed to go to this outdoor exhibit, but it got rained out, so we ended up back at my apartment.

It was the middle of the afternoon on a Tuesday. We made grilled cheese sandwiches and put on a movie.

I was still wet from the rain, so I said, "I'm just gonna change into something else." I walked into my bedroom. I was just gonna put a T-shirt on. I opened the drawer, and I saw that blue slip. And I thought, What if I put that on? I was like, Why would you do that? It's the middle of the afternoon on a Tuesday. I thought, Well, I own that, and I've never worn it.

And what is this sex thing? I can do that. I can say yes to having sex. And what I love about saying yes is when you do say yes, everything can change. And so I took that slip out, and I put it on. And I walked into the living room, and he said, "What are you trying to do to me?" And I was like, "Shh." And we started kissing. And we lay down on the couch. And the moment was building, and we were kissing. And I leaned into his ear, and I heard myself say, "You need to pray and find out if God exists." And he was like, "What?"

So I was like, "Never mind." And we started kissing again. And the moment started to build again. And it was all going well again. And it happened again. I leaned to his ear, and I heard myself say, "How can you know if God exists unless you've prayed?" And he was like, "WHAT?!?!" And I thought, What am I doing?! All I wanna do is have sex right now, and instead I have God Tourette syndrome! And he sat up, and I sat up, and he asked, "What are you trying to say?"

And I said, "Well, it's just the only reason I believe in God is because I prayed, and I asked, and I got an answer. And so all these choices that I make are a result of that feeling." And he asked, "Do you want me to pray?" And I said, "Yes." And he said, "OK. I can do that." And I was like, "Really? OK."

And so we said goodbye and he left. And the minute he left, I said a prayer. I said, "God, I know I pray a lot, but can this one count for a whole lot more than the other ones? And you don't even have to listen to anything else I ever say, but if Nick prays, will you answer him?"

And then I called my mom and dad, and I was like, "Can you pray?" And they said they would. And then my parents called my grandparents. And literally there was a Mormon family tree across the United States, praying for me that if he prayed, he would get an answer. I didn't hear from him for two weeks. When I did, we agreed to meet up. And we met up and sat on a bench, and we were just small talking.

And finally I just broke through and asked the question that I really wanted to ask. I said, "Did you pray?" And he said, "Yes." I thought, Wow, because he's 29, and his whole life he's never once tried to pray. I said, "What happened?" And he told me that he sat in his room in silence, and that he prayed, and he asked if God existed. And he sat there for a long time, and he listened. And he realised that even if he did hear an answer, it would just be him telling himself that he had heard an answer because he wanted to be with me, and that it wouldn't be real.

And that was it. We broke up. And, upset as I was that he didn't get the answer I wanted him to get, I totally understood where he was coming from, because he tried as hard as he possibly could to find God for me, and I tried as hard as I possibly could to have sex for him. But in the heat of the moment, all I could do was bring up God. You know, my whole life I'd thought that I didn't have sex because I was Mormon, but I realised in that moment that I don't have sex because I don't want to. And sometimes saying no can actually be saying yes.

• This is an edited extract from The Moth: This Is A True Story, edited by Catherine Burns, published by Serpent's Tail at £12.99. To order a copy for £10.39 with free UK p&p, go to theguardian.com/bookshop or call 0330 333 6846.

Read Molly Ringwald and Neil Gaiman on why they love The Moth, plus true stories by Malcolm Gladwell, Nobel prize-winning geneticist Paul Nurse, Kimberly Reed and Kemp Powers.