Bob associates the word "handsome" withing being ideal to the person talking, and Bob notices how many girls are interested in Charlie, and inadvertently starts thinking in the terms that Charlie is handsome because of that.
Bob and Charlie are long time friends, while Bob normally refrains from speaking his thoughts about Charlie, he does so forgetting that it might sound homosexual to somebody who doesn't know Bob, rather than the fact that they are friends and Bob uses less mental restrictions when thinking about his close friends.
Inverted: Bob, who is known to be gay and in a loving relationship with Charlie, remarks on how attractive Alice looks (which could be called a "Straight Moment").
Subverted: What Bob said about Charlie was entirely non-sexual and was just taken the wrong way. "What? When I said he had a nice ass, I was talking about his pet donkey!"
Double Subverted: Charlie says "But, Bob, I don't have a pet donkey!"
Zig Zagged: Bob makes a comment about how attractive Charlie is. He quickly backtracks. Later, Bob starts going out with Alice, who seems fine with occasional Gay Moments between Bob and Charlie. Even later, it transpires that Bob is gay and Alice is his Beard. Bob approaches Charlie, only for it to turn out that Charlie was straight all along.
Averted: Bob makes no comment regarding Charlie that would make him sound gay.