Hardbodies (1984)

"If you don't know what they are, you don't know what you're missing."

Three middle-aged daddies visit California to have a marvelous time at the beach. When they learn that a nice apartment and an expensive cabriolet isn't enough for them to score with the chicks, they employ a student to help them. At first he's as disgusted of them and his job as his girlfriend, but soon they find out how to use the situation to everyone's benefit.