The "kissing" is actually a sign of dominace and to help establish a pecking order. The bigger the lips, the more dominate the fish. In human terms, it would make Mick Jagger emperor of the world.
In small volume tanks, pink kissers can be a real pain in the rear with tankmates, but in larger tanks, I've no trouble with them at all.
You just have to take into account that when all is said and done, you're gonna have a =huge= fish on your hands. I've seen abandoned pink kissers at other stores that you can't even believe are actually gouramis.
~~Colesea