Yes I believe it happens. Certainly it did in the days of the studios having a lot of control - particularly to cover for gay members of the industry - not just the actors.
Rock Hudson
Cary grant
Vincente Minnellli
I have strong suspicions about current stars too, particularly sports now as there's still far too much homophobia there. But there's an 80's till now film star I'm actually a big fan of, not popular on mn but I suspect they're gay and their relationships have been for show, with agreements between the participants. They get to hide the gay, their spouses got a HUGE boost career wise.
I think George & Amal are a genuine one, she was doing pretty well for herself in her field before they got together, he did always strike me as a commitment phobe rather than gay and it's not uncommon for these types to want to settle down when older and facing their own immortality - and want to procreate at that point too.
And misogyny being alive and well, it's easier to be a gay man than a gay woman in celebrity circles now. So if TS is I can well understand why she's keeping it discreet - but it's not on to mess with people's emotions (if she is) by being less than honest about the situation.
SuperSuperSuper - because it's all relative, however much money or game or success they have - they can still want more! Otherwise celebs would just retire ridiculously early if they're very successful in 20's/30's and just live off what they'd already earned/royalties.
"but can anyone really live a lie that deeply now days when its so easy to follow people and take pics..." It's possible if you have deep enough pockets AND are known for being litigious - you may not be able to buy them all off but you can certainly make people want to avoid getting sued, especially by someone with enough money to take it all the way!
As a bi woman myself, while it is lovely that mners think it shouldn't be an issue, I can assure you even in the uk lgbt people still get a rough time - on nights out, from family, affecting careers... We're not COMPLETELY enlightened yet. And as pp said in many other countries (where these stars are selling themselves/their product and may be visiting) it can still be very taboo, even illegal.
"Ask Rupert Everett whether it harmed his career. Or more recently ask Kristin Stewart and Ellen Page." Exactly!
Letsallhaveanap - remember it's not just the stars themselves that consider the ramifications but also those hiring them - the studios/record companies won't hire people that can't sell the product or worse will actively turn buyers off.
The clooney's married in Italy. Not sure what the laws are there re divorce, pre-nups etc or if his being American and her British are factors?