Anne Bennent ENF in Lulu (1980)
 

A 1980 movie by Walerian Borowczyk who gave us a great mass nudity scene in Immoral Tales (1974). It's in French but it's not hard to understand what's going on.

Two scenes grabbed my attention. The first one starts with Lulu modeling for a painter but they get into an argument, then he rips her clothes off... they fool around, then just as they're about to have sex her husband (some rich old guy) comes back.

The second one, she's caught having sex (again), she has to hide naked but then someone leaves with her clothes. She tries to sneak out but gets caught, the dress thief giving her back her clothes.