I personally don't mind PDA's within a reasonable limit. No tongue kissing or sticky fingers

. If bodily fluids are getting involved it's gone too far and will almost certainly put me off my lasagne.
Couldn't care less if it's same sex couple or heteroses though.
I did once have the delight of seeing a guy getting quite blatantly wanked off under a coat by a girl in a bar once. It was only about 7pm and I was just enjoying a game of pool and some curly fries! I think they thought they were being subtle

.