When you take a shot of alcohol into your mouth and give somebody a kiss, sharing it.
Man, David's really feeling it today. He's had 8 shots and gave a chick a viper's kiss.
When a woman gives a guy a blowjob, and after he ejaculates in her mouth, she cocks back her head and spits the load of semen in his face like a viper.
She gave him a viper kiss after sucking his cock last night! She spit it right in his face!
Similar to Poseidon's kiss except that you pissed in the water beforehand, so now the piss-infused water splashes up and touches your arse
"spent 20 minutes on the toilet yesterday and i got a Viper's kiss