Russell was telling us how much in love he was with Holly when Keith speaks out loudly "How about some of that Whitesnake". Damn, Russell just got "Whitesnaked"
To "do a whitesnake" is the act of leaving your friends or colleagues at a bar or club and not tell them your leaving.
This is done in order to bypass lengthy goodbyes or to avoid a peer pressure situation to stay and consume more alcoholic beverages when you just want to go home.
A usual tactic is to excuse oneself to use the bathroom and then not return.