I'm not sure it would be Cap. Bis is actually an abbreviation of bisou however is is never used as such with adults. Bisou is generally used when taking to very small children - up to six year-olds. After that, it switches to bis or bec.

Notable exception: Those couples who insist on taking baby-talk to one-another. English comparative...those couples that say "come gimme a kissy-wissy my baby-waybe." Makes you rethink those free-speech laws.