Exactly.
Worst case scenario.
A male Premier League player turns up to an event with his male partner, three things happen. The MSM gutter press would be all over them, not in the fire and brimstone fashion of yesteryear, but in constant intrusive articles about both of them, particularly if the player was signed to a high profile club. Their private lives would be over, the pressure would never end, constant attempts would be made to get the player and his partner to make a statement of some sort, his team mates would be expected to show support, as would his manager, and woe betide them if the MSM judges them insufficiently effusive. Overnight this player would no longer be a footballer, he'd be the gay footballer.
Social media would be all over it, endless bollocks about them would be spouted.
And the politics of it would kick in, pressure groups, from the legit to the downright wacky, would seek to co-opt him whether he wanted it or not.
Or maybe nothing out of the ordinary would happen.
I suspect not knowing which way it would pan out, goes a long way to explaining why it's not happened.