Late seventies, early eighties. Probably straight to video. Story is about a man’s descent into voyeurism. The main character is, if I recall correctly, a TV news reporter. Two scenes stick in my memory. One: He’s making love with wife or girlfriend and instead of focusing on her he’s watching their reflections in the mirror. Two: He gets his ass kicked after being caught at local lover’s lane spying on couples. The lead actor, again going by memory, looked a lot like James Naughton. But nothing in his IMDB seems close. (Here’s a pic of him from that timeframe.)
I also checked David Naughton’s IMBD but no luck there either.