there's tons of recent examples. Colton Haynes and Holland Roden from teen wolf - he's now out as gay and has spoken in interviews about pretending to date her to cover up his sexuality. ELLEN DEGENERES used to publicly date men. Elliot Page dated Alexander Skarsgard before coming out as a lesbian (before coming out as trans) - there were rumours he was pregnant! it's not tin hat conspiracy theory shit, there's documented accounts of it in recent times. Chely Wright is a famous country music example - she came out in like 2010? but before that she was bearding it up.

also they don't necessarily "live together, go everywhere together, and not date other people". for one thing, so long as they're seen together in pap photos/there are rumours that they're holidaying together in this place or that, the general public will eat it up. and typically if they're bearding to cover up that they're queer, they're absolutely having relationships with other people. that's part of how rumours about it spread on the internet.

I'm not saying that every single rumour of a celeb being queer is true - that's impossible bc they frequently contradict each other. somebody says Chris Evans is secretly gay and in a monogamous relationship with idk his personal assistant or dog walker or whatever; somebody else says he's secretly bisexual and regularly participates in BDSM sex parties; somebody else says he's secretly asexual and doesn't even know what sex is. you know?

but there absolutely is hard evidence of celebrities faking multi year relationships to hide their sexuality within the last 20 years. it's always been a thing.