I'm not too comfy with being overly affectionate when out in public. We hold hands and such, but that's the furthest we go.
A quick peck, hug and some petting is fine by me, but full on tongue wars pisses me off. You know they're doing it to show off when they smile afterwards and glance at everyone - usually very quick but you can notice it. Almost like "ooooh look at us, we're perfect and you don't have either of us". Ironically it's usually the fat ugly ones.
I'd love to say something like "give me a fucking bucket" and see their reactions. Haven't seen anyone say anything about it, only really groan or eyeroll at most.