verb. When a man has sex with woman from behind, while she gives a blowjob to another man. The term is used as a verb often as a discreet way of announcing the sex act regardless of who may overhear.
Additionally, this term may garner hilarity on the part of anyone who isn't familiar with the term.
Joe (clearly audible to all): "Steve, the girl at the other end of the bar is up for us taking her to swiss chalet."
Overhearing Grandmother (for some reason in a bar): "Oh, you boys are so sweet. My husband would take me to Swiss Chalet every Sunday, before he passed."