Flaming Brothers (1987)

A man comes out of the bathroom in a towel; he then comes in with two other women calling him "Superman". The women start disrobing and making out in bed, nothing explicit but a lot of giggling.

A man makes a woman simulate moaning over the phone.

A woman asks to "have fun" and they compensate by making love in bed. Nothing explicit, but the characters are stripped to their underwear.