Viper's Kiss
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.
Viper 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!