That question was asked of me years ago while giving a sneak peak of Season 19 to a friend of mine. There were two ways to answer that question: The smart way, and the stupid way. You have probably already guessed which one I went with.
"These are my characters and I'll have them do what I want."
While true, It's a very dumb reason. Ravy Comics has developed over the years as more of a character driven comic. Such as my personal favorite Bloom County; rather than a random comic like the great Far Side. When someone asks a question as to why a character does something, you have to be prepared with an answer. A real one. Comic number 1607 being posted on January 13 2011 answers the question as to why Toni gave up being a lesbian and married a man.
Simply put she fell in love with Op.
However there is an answer behind the answer. I based a lot of this particular comic and ones over the years on real life events, situations, and conversations I have been party to. One such case is a lesbian friend of mine and I were have an engrossing conversation about the ins and outs of our favorite subject: sex with women. When it just popped out:
"Do you think it's possible for you to fall in love with a man?" She said yes. "Then I have a chance." I remember coming to hours later with a big purple bruise on my forehead. Months later another friend of mine seemed down in the dumps. She told me that her partner got herself pregnant and married the guy. I asked her who she wanted me to make cry and how about some revenge sex. I remember waking up hours later with now two purple bruises on my forehead.
"These are my characters and I'll have them do what I want." Has haunted me for years and now I think I can lay it to rest.