Idea #1:
Joe is mostly attracted to women but occasionally screws men. Gay sex squicks me, so emphasizing the latter will lose me as a reader
Anyhow, the guy's father (or uncle, or friend, or whatever) Bob finds out about the Joe having sex with a guy. Bob's basic mental thoughts are along the lines of what I'm sure is a common thought process in the real world: "Hey, stop being bisexual. You'll still be happy if you're heterosexual and you won't have to put up with as much crap"). The alternative version of that argument is, "Hey, keep being bisexual. Get another girl and lets party!"
Anyhow, Bob's solution instead is to get lots and lots of women to screw Joe. Joe is finding himself thrown into orgies where he is the only man. He gets to see women fight over him for sex. A cat fight over him where women tear off each other's clothes (half the fight is serious, half is about making Joe want them) would not be misplaced. Random women are throwing themselves at him. Apparently, Bob knows a lot of women. It helps that everyone vouches for Joe being a good lover.
Anyhow, a while later Joe screws another man (details on this encounter would be probably scare off most of your audience). Bob has a conversation with Joe much like this:
Bob: Joe, why would you want to screw men? Women make you just as happy and there's no fear of controversy.
Joe: I like men too. Besides, this way maybe you'll throw more women at me.
Bob: You knew about that, huh?
Joe: Women are far worse at keeping secrets when they're experiencing orgasms. All those mutterings about thanking Bob...
Idea #2:
Joe is bisexual but mostly prefers women. However, he deliberately gives off the impression that he is gay, never mentioning his female partners but occasionally mentioning the male ones. Anyhow, he somehow, without lying (but thoroughly misleading) gets women to think they can turn him (i.e. makes them think he's gay but that he's feeling a bit of interest so that they'll try to make him straight, as opposed to just admitting he is bi). The result is sex for Joe from such women.
Joe is mostly attracted to women but occasionally screws men. Gay sex squicks me, so emphasizing the latter will lose me as a reader

Anyhow, Bob's solution instead is to get lots and lots of women to screw Joe. Joe is finding himself thrown into orgies where he is the only man. He gets to see women fight over him for sex. A cat fight over him where women tear off each other's clothes (half the fight is serious, half is about making Joe want them) would not be misplaced. Random women are throwing themselves at him. Apparently, Bob knows a lot of women. It helps that everyone vouches for Joe being a good lover.
Anyhow, a while later Joe screws another man (details on this encounter would be probably scare off most of your audience). Bob has a conversation with Joe much like this:
Bob: Joe, why would you want to screw men? Women make you just as happy and there's no fear of controversy.
Joe: I like men too. Besides, this way maybe you'll throw more women at me.
Bob: You knew about that, huh?
Joe: Women are far worse at keeping secrets when they're experiencing orgasms. All those mutterings about thanking Bob...
Idea #2:
Joe is bisexual but mostly prefers women. However, he deliberately gives off the impression that he is gay, never mentioning his female partners but occasionally mentioning the male ones. Anyhow, he somehow, without lying (but thoroughly misleading) gets women to think they can turn him (i.e. makes them think he's gay but that he's feeling a bit of interest so that they'll try to make him straight, as opposed to just admitting he is bi). The result is sex for Joe from such women.