Bi the way [Female wanted]

This is just a basic idea I came up with. My character is a straight male who's entered a non-exclusive relationship with a bisexual women. In fact, his girlfriend actually has a relatively large preference towards women (basically, she's attracted to women, and this one guy).

I don't really have a full-on plot for this yet, but I like the pairing enough that I'm putting it up here. I'm thinking a lot of hilarious conversations between them about other women they've met, and how his girlfriend probably has more luck with the ladies than he does.