Look, I don't care how someone wants to express themselves. Would I like seeing a 50' billboard of two naked men kissing? Nope, but so what if I like it or not? Someone else obviously does.So if I wanted to pay for a 50' billboard inside the Capital building showing two naked guys kissing in a loving embrace, you'd be ok with that? You know, my money, my expressing myself on public property? Or how about a 50' billboard memorializing the 19 hijackers from 9/11? There are lots of idiots with money in this country, but that still doesn't mean that we should be subsidizing their idiocy... (and no, none of the groups in question pay for the space that they're using)
It's not fair to others for me to just walk around deciding who can and who can't express themselves, and it's not fair for others to do that to me.
Now... you may get into legality issues with the men being naked, but if it's a waist up photo of them kissing and I try to restrict a photo like that being on a public ad, then you might as well censor all photos of kissing from public ads because a lesbian woman may not like seeing a man groping a woman just as much as I don't want to see a man groping another man. Censoring all kissing would be much worse than not censoring any kissing.