The Party (1968)

A woman sunbathes on the film set.

A fountain replica of the Manneken Pis; it later soaks a party guest, after the protagonist activates it on a panel of electronics.

The protagonist gets desperate to use the bathroom; he eventually finds one. It is implied as urination, but we don't see nor hear any sounds, except the look of relief on his face.

A man tries to make out with an actresss.

The protagonist is forcefully disrobed into a red long Johnson.