(verb), comes from a type of tea, also called Lapsang, a variety of Souchong China tea with a smoky flavour. Where our ancestors enjoyed the flavour, in modern usage, "to Lapsang the Souchong" means when your girlfriend takes a swig of lapsang tea, and then takes you in her warmed up mouth, with the tea still in there, and gives you a juicy blow job. one of the most pleaurable experiences my ex ever gave me, before i dumped her sorry ass.
"dude, me and jessica were getting horny last night, and she turned on the magic - she lapsanged my souchong until i came all over her face!"
"i really love it when my girlfriend asks me if she can Lapsang the Souchong!!"