Very Close Encounters of the Fourth Kind
Italy 1977. Director: Roy Garrett (Mario Gariazzo)
Cast: Maria Baxa, Monica Zanchi, Marina D'Aunia
Aka: A Coming of Aliens

Here's the real thing for all alien collectors around the globe. Helmer Mario Gariazzo is a devoted UFO fantast and has directed at least two more films on the subject, Eyes Behind the Stars and My Brother From Space. This time he goes for a more fun approach, having three funny students impersonating aliens from space so they can fool their boring but sexy teacher and UFO believer Professor Emanuelle (Maria Baxa) into having sex with them. Don't ask me why she want to have sex with aliens, but she does really bad. Emanuelle has a sister too (pretty Monica Zanchi from Emanuelle and the Last Cannibals) and from there it gets real funky. The aliens enter the girl's house and investigates their bodies while whistling to each other. Then there is an overacting farmer who has a wife (Marina D'Aunia, so good in SS Girls) who's also interested in sex from another planet. What else do you want to know? If it's anything worth buying? Well, one of the actors is credited as... The Phenomenal Jimmy. It's precisely that kind of film. A classic.