Duck kiss
A kiss where one clamps down their lips around both of their partner's as though they are a duck closing their bill around the other lips. This could be viewed as a possible variation of the more common kisses where a person takes one of their partners lips in between theirs.
Expecting a kiss on the cheek, the girl was shocked to find her lips suddenly ensnared when the her date gave her a duck kiss instead.
Duck-bill kiss
When a guy purses both lips out to look like a ducks bill to give a kiss to a woman after she's sucked his cock. This is done to insure that she doesn't try to sneak her tongue in there and get his own cum in his mouth.
Shaniqua came up to give Gerardo a kiss after he blew his wad in her mouth. He didn't want to taste jizz though so he gave her a quick duck-bill kiss and told her to go brush her stanky teeth.