Is it considered Taboo?

I have absolutely nothing against gays and lesbians, I actually don't get along with people that are homophobic. I'm just curious because I was watching the show taboo and they said that they consider relationship taboo (or whatever you call it, in love with objects and what not) to be a relationship where the couple can't produce children. So would people consider to be gay or lesbian taboo? That just doesn't seem right because it seems like a fairly common thing.