My nerdy lesbian girlfriend and my stepbro get it on

I've got a girlfriend who's about as nerdy as they come. She's always buried in her textbooks, and I'm more than happy to let her get it on with my stepbro. It's not exactly the most conventional of situations, but hey, we're a pretty fucked up family. So when she's done studying, she's got a little bit of fun with my stepbro. And when my girlfriend's not around, she's more than happy to get it on with my stepbro too. It's not exactly the most taboo of situations, but it's definitely a bit strange. But hey, if you can't have a little fun with your friends, what's the point? So my girlfriend and my stepbro have been getting it on quite a bit lately. And while I don't mind, I'm not exactly a fan of the whole lesbo thing. But hey, it's their thing, I guess.