Marcel

A frenchman working as the Maître d' at a fancy restaurant situated in a natural cave, close to the ocean. His wife, Josianne, works as a waitress at the same restaurant. They are first encountered in the background when the protagonist takes Allison on a romantic date to the restaurant they work at.

Later they are encountered again in the park and this time they have a proposition for the protagonist. It turns out that Marcel cannot get an erection without watching his woman have sex with another man! (And he apparently needs multiple times to have full effect.) They want the protagonist to have sex with Josianne while Marcel watches.

While Marcel is very eager for this to happen, Josianne is more reluctant (as she is a virgin) but, at least, the protagonist is the first attractive man Marcel has suggested so she is willing to consider it.