Had I come of age in a world that supported same-sex relationships and gay marriage, would I have been able to commit myself to one person for a half-century? Would I have been able to raise children? Certainly, I could have enjoyed the opportunity to start a relationship when young and "strong" with someone else who was likewise, and actually exciting, and experienced the relationship for its own sake, for the sequence of moments. But could I have made it last? I don't know. When I lived in Dallas int he 1980s, there was a male couple together for 49 years (despite the prejudice) before one of them died.
I can say that I have never known jealousy. But that itself is double-edged.