So this is right at the borderline of things I suddenly realized were bi upon changing

(Headliners are:

• Porn theaters and private booths: jerk off to straight porn while gay guys watch offering bjs? Stick your dick through a gloryhole not knowing who’s on the other side? Who is this for, I asked. Now I realize it’s like the bi equivalent of bathhouses.
• A surprising amount of ‘80s-style antigay stuff. Like, preachers who proclaim heterosexual marriage as the foundation of society but were picking up dudes away from their wives? Guys speaking with conviction about how social pressure was useful and necessary to fight temptation and keep men pairing with women and not men?

)

but I’m just now grokking that cuckolding or “sharing” girls are both ways for guys to give and take pleasure from other guys, using a girl as an interface medium.

There’s more than that in there – there’s the prickly kick of violating social norms, the eroticization of your fears and inadequacy, the turnon of having your ideal type – a girl who gets around – as a partner, etc. But among things there is that.