Parodied: Bill is an over-the-top masculine stereotype who can make any man his bitch.
Zig Zagged: Bill is a blatantly stereoytpical seme who plays pitcher to Andy... but only the first time they have sex. The next time, he's on the bottom. After that, he's on top again.
Averted: You can't tell who's the Uke and who's the Seme if you skip the sex scenes.
Enforced: "Women are going to be reading Boys Love 99 percent of the time. We need a manly character who is dominant in bed, because the ladies like to see the pretty uke get "swept away"."
Lampshaded: "Of course I'm on top. A real man never takes it up the ass."
Invoked: Bill knows Andy is attracted to Semes, so he purposely acts more like one.
Defied: Both Andy and Bill are developed believably as rounded male characters, and their sex scenes aren't shown in the work at all.
Discussed: "Hey, Carol, do you think Bill is Andy's seme?"
Conversed: "Of course Bill's the seme. He's the tall, manly one."
Bill doesn't want to only be on top, but Andy won't sleep with him unless Bill tops. This drives a rift into their relationship and they break up.
Alternately, Bill and Andy's relationship is based on If It's You, It's Okay and Bill still sees himself as straight, so he only sleeps with feminine Ukes. His issues accepting his relationship with Andy drives them apart.
Bill realizes being with Andy is worth never being on the bottom and they get back together.
Bill realizes he is attracted to Andy not because he's just a hole, but for his whole person.