On the best of days, being not officially Tom’s parent is a tangled thicket of boundaries, expectations, and my inability to resist unbridled cuteness. I vacillate between being a pushover and a bigger pushover.

Sometimes I watch Tom for a few hours because my Tom meter is low, and sometimes I do it because Renee wants to take a shower, put some laundry on and catch a two hour nap. But since I’m not Tom’s father and I never signed on to raise a kid, sometimes I also smile and say, “I’m sorry. I have things to do.” And if you want to know the truth I don’t talk about at parties, sometimes I hold off on swooping in with my cape and my UC chest insignia (Uncle Chris) because I know right now I’m sort of being taken for granted, but in two more hours of Tom being fussy, the gratitude will really be totes genuine.

On my best days, I’m flying from judgment call to judgment call by the seat of my pants and figuring out if I made a good choice only in retrospect. I try to be there for the hand off when William is exhausted from being up all night with Tom gnawing on his finger, but I also play the part of the asshole when William is tired from being up all night playing Skyrim. (It is during these times that I must use nearly all my reserves of willpower not to say a throaty “Sorry, Brah….”) By now I’ve probably jumped up to help with Tom when they were doing pretty okay without me, and I’ve probably left them twisting in the wind when they could have really used help, obliviously snuggled into bed for eight delicious hours with my white noise maker roaring its highest setting next to my head.

Some days I worry that I’m a terrible person because I take space or time to myself or don’t consider Renee’s New Girl marathon to be a worthy reason to have to change a diaper at five in the morning. And it doesn’t help that Tom has perfected crying at the frequency of human mind control. But given that both William and Renee are getting a full night’s sleep and have social lives with a teething three-month-old, I feel like I probably won’t come home to find all my video games and books on the front lawn.

Every once in a while this status quo is challenged.

“You’re a dad,” Renee says when I post on Facebook my thousandth baby picture…that day.

“Pah,” I scoff.

“That sounds like something a dad would do,” she says when I walk around the block with Tom in a carrier for three hours because that’s what actually puts him to sleep.

“Nah,” I gibe.

“You’re such a dad,” she says as I play with his feet to get him to smile when his diaper rash is making a changing particularly rough.

“Renee…” I say, leveling a serious look at her. “I am looking forward to every moment of helping you raise this kid. I want to be there when he sees Empire Strikes Back‘s big reveal and when we go to the aquarium and he first lays eyes on fish that are bigger than he is. I want to take him to all the museums and help him learn to read and show him zoos and tell him stories at night of my own design like the dad in that Roald Dahl book about the pigeons. And I’m so excited to do those stupid kiddie rides at Disneyland! And—oh my god!—I can’t even wait until he’s old enough to handle scary things like Reavers and I can show him Firefly. I’m even perversely looking forward to teaching him what the Bechdel test is and why Avatar is post-colonial crap.

“But I will always be helping you,” I remind her. ”I’m not Tom’s father.”

These conversations are always somewhat painful to me. I love Tom, and when I look at him, I have to fight the urge to spout cliches about “nothing ever being the same,” and shit that used to make me roll my eyes at parents. But they also remind me how edged out I am.

In theory, I don’t have any trouble with the idea of being a co-parent to Tom. He’s obviously the cutest kid that has ever been born in all of time; I feel a little sick at just how much my heart implodes when he recognizes me and smiles. I already change Tom’s diapers, suck snot from his nose with a rubber bulb, and have given each of his toys their own personality and accent. And if there was a rulebook for what a family ought to look like, I obviously packed it away with the James Joyce novels after college and shoved it behind the Tony Jacklin golf clubs somewhere on the “sketchy” side of the garage. There is a mountain of legal paperwork that will make me Tom’s guardian if the worst should happen. But right now with both Renee and William parenting, I definitely feel like I’m…well, like I’m an uncle.

There have been important decisions about Tom that I didn’t really get to be a part of. When Renee asked me to be a co-parent to a baby, and I said I wasn’t ready to be a parent yet, she got pregnant anyway. When I objected in the strongest terms I knew how to the idea of a home birth, I was overruled. It’s hard to feel included when the biggest decisions so far have been made over my objections.

And seriously, I’m okay with letting Renee and William handle glowering principals, the porn talk, and the crippling insecurity that their every decision will put Tom in therapy, while I get to be the cool uncle who buys him chemistry sets and Lego series under the condition that he lets me help break them in.

Still, when Renee blasts me with her devastating puppy dog eyes, I remind her that to even consider changing my position, she would have to start including me in more decisions. Yet they still go on around me. Everything from where Tom sleeps to how to handle his first cold. One of the things that is unfortunately true about poly triads (whether they are V’s or everyone is involved with everyone) is how hard the preexisting couple has to work to truly include the third.

This disconnect also goes beyond Tom. It’s not that I don’t see Renee and William as my family; I do. It’s just that there’s a part of that relationship that has never progressed past them being the married couple and me being the guy that’s renting a room in their house. Everything from being the househusband who is expected to wrangle up his own retirement to the fact that the perfectly functional upstairs bathroom gets refurbished while my request for a functioning doorknob is ignored contributes to the feeling that I’m on the outside looking in.

Unfortunately, I feel like we’re kind of on a time table. Tom may just be starting to chew with wild abandon on teething rings, and not quite up to a full-fledged giggle, but it’s going to be a blink before he’s asking questions. While we would never keep the information from him about which of us contributed 23 chromosomes, I also want him to be able understand his place in our world, and ours in his.

It can be difficult on the best days to stand fast to boundaries when it comes to the needs of kids. Sometimes it feels assholish and mercenary of me to advocate for my own boundaries, especially when it’s not Tom’s fault his dad is grumpy because he discovered new episodes of Archer on Netflix right before bed the night before. In my brain I realize that most nuclear families never have the help of a third person, and I know I’m helping, but brains are so unwelcome in parenting anxieties. It’s tough to keep myself in mind when I want the best for Tom.

Usually these moments of genuine gravitas—where I remind Renee of all the things that would have to change for me to even consider stepping up into a co-parenting role—end with her confidently saying, “I’m not worried.”

And me biting my tongue not to tell her that I am.