The Party at Kitty and Stud’s, better known under the title Italian Stallion, is a 1970 softcore film, which has the distinction of being Sylvester Stallone’s first film and also his first starring role, for which he worked two days and was paid $200.
Stallone has said in interviews that he did the film out of desperation after being bounced out of his apartment and finding himself homeless for several days, sleeping in a bus station. In Stallone’s words: “It was either do that movie or rob someone because I was at the end – at the very end – of my rope. Instead of doing something desperate, I worked two days for $200 and got myself out of the bus station.”
The film deals with the sex life of New York girl Kitty (Henrietta Holm) and her boyfriend Stud (Sylvester Stallone). Stud is brutal and oafish but Kitty is enamoured with his sexual performances. They sometimes engage into light sadomasochism, with Stud belt-whipping Kitty. Stud later posts a sign on a bulletin board inviting people to a party. Several people show up at Kitty and Stud’s apartment and they all engage into group sex, with Stud servicing all the women.
Summary via Wikipedia.