Too bad the bit between 2:30 and 2:50 on this scene from La Moglie del Dentista wasn't extended some minutes.
There's not any scene like that. Another sex moment/masturbarion moment I can think of is Jessica Rizzo in La Moglie del Sciciliano.
it's as if director dont make the most out of sex scenes in cinemas, theaters, waiting rooms, restaurants, dressing romos, dentist's office, etc.