Was there ever any concern about making the wedding of Aria and Ezra, her former teacher, the endgame, considering that their relationship started out as statutory rape?

It was such a big part of Sara’s first book, and that book became the pilot, so we just sort of owned it. I wanted to be true to the characters that Sara created, and it was the biggest part of Aria’s story. It is what it is. I think they’re meant to be, and that’s that. Yes, there is some criticism about [the relationship]. We got a lot more pushback on Emily being gay than the Aria-Ezra story. ABC Family was really a conservative channel, spun out of the Christian Broadcast Network. And so, yeah, I got a lot of angry letters from conservative Christian moms who couldn’t believe that two girls kissed in the pilot. They didn’t care that Aria and her teacher were making out — they cared about two girls kissing. It says a lot about our society, for sure.

And yet that was one of the more nuanced story lines, Emily’s coming out, and her relationships.

It was important to me. There were two things I wanted to establish in the show and maintain as a recurring theme. One was, these girls — at the time they were girls, then they became young women — are going to be unconditional friends no matter what. It was a great opportunity to model what friendship looks like, and women treating women positively. Equally important to me was that Emily is a Pretty Little Liar, just like the rest of the characters. She just so happens to be gay. And when she comes out to these characters, they are going to accept her unconditionally. I’m still very proud of that. I’ve gotten so many letters about what a positive influence this show has been on their lives.

A transgender villain, Charlotte, however, was a little more divisive.

Oh, absolutely. We were not expecting that. The overnight reaction to that finale surprised me, because just like being gay, I thought we were making a statement about transgender. I think of transgender characters the same way I think of gay characters and straight characters — as if we’re all equal. Yes, she’s “A,” but she just so happens to be transgender. If we had more seasons to come, I think I would do everything I could to promote positive gay role models, people accepting people being gay and transgender. I would feel like that was my responsibility, to just promote kindness.

You make a cameo during the wedding scene, when your phone interrupts the proceedings.

I didn’t want to do one, but the fans were so insistent. And the Pretty Little Liars. They were like, “Do it. Do it.” It wasn’t until we were in prep for the finale, two days before we were shooting that scene, and then I was like, “Okay, this will be it.” Also, my son Emerson is in the classroom with Allison. And my wife and my younger son Atticus were in the French doll shop. So it was a family affair.

“Pretty Little Liars” could get pretty convoluted, so much so that you developed a shorthand for how to dump story lines that were just too over-the-top, by saying they belonged to an imaginary alternate show you call “Strawberry Patch Lane.” How did you decide what belongs and what doesn’t?