What terrible advice.

One of the things I'm wondering is how much Carlos has already had to lie to Emily. He had at least one serious relationship with a man, and two to three (he doesn't remember?) he describes as "flings" but also says were "similar" to his serious relationship. That's a lot to hide. Is he just omitting those months/years of his life? Is he turning his boyfriends into girlfriends? And it seems pretty clear, or else he wouldn't have written the letter, that these aren't relationships he wants to forget or to lie about. It's a big part of his life experience, not a one-night stand that didn't work out.

I'm also struck by Carlos saying of his serious relationship, "It started out very innocently, with a few drunk hookups but it was a pretty serious thing." So a drunk hookup with another guy is "innocent," but a relationship with one isn't? It's okay to sleep with a guy but not to date him or love him?

I don't want to read too much into a word choice, but I think Carlos is struggling with some internalized issues, not just with Emily's biphobia.