General affection/touching/hugging/snuggling up is fine but full-on tongues or heavy groping is a bit much innitt.
Me and a mate were once having a quiet pint and saw a young (Uni-age) couple sat together with her "secretly" wanking him off under a couple of jackets on his lap. We were the only ones in there other than them, it was the middle of the afternoon! You
expect a bit of groping and heavy petting on a late evening but not when you're just in for a burger and chips
.
Then one of the barmaids, who has seen us laughing, notices what we're looking at and comes over to politely but firmly tell them to get the **** out
. They both looked mortified but they were being so un-subtle
.