Caledonian Sleeper
At a Scottish wedding when a drunk Groomsman targets a passed out/sleeping guest at the reception (after party). The aforementioned lifts his kilt and proceeds to put his flacid penis in the unsuspecting sleeping victims mouth. Once fully inserted the Groomsman then motions as though he is activating the pullchord of a locomotive and yells "Choo Choo. All aboard!"
Cameron was looking forward to Donald and Morag's wedding. However he would not be drinking incase Hamish inflicted a Caledonain Sleeper on him if he passed out. Hamish was famous for his Caledonian Sleepers at weddings.