From what I've read, gay people were born with the predisposition to eventually find out they're gay (usually), and gay people don't 'become' gay. They might come out or start engaging in related behaviours.

Watching a Quebec series from 2014 called Serie Noire, one of the characters complains that his girlfriend has become a lesbian, after he finds out she's cheating on him with a woman. He remarks multiple times about how he's distraught that she has become a lesbian and it's probably played for comedic effect. Of course the issue shouldn't be that she's a lesbian (or bisexual) but rather that she's cheating on him and isn't interested in him, but he also calls it "becoming" a lesbian, describing it as a somewhat random event/decision rather than a reveal about his partner.

Just wondering, would this be considered offensive today? Thanks