Perversions d'une jeune fille mariee (1978). The guy is a regular in those Alpha Blue films. I thought the Porn Biz line was that for male performers size was less important than the ability to deliver on time, as required.
LOL! looked like he winked at the end. The one girl kinda looked like donna from that 70's show so I was pretty stoked about that...uh...yeah...good times