In addition to frolicking on the beach in Hawaii, there were several roles in which Grant removed his shirt, removed his pants, and removed it all in one 1980's film. I am sure there are more, but here are a few of my favorites, including Grant showing his scrumptious and round rump in that 80's crime flick.
With Morgan Fairchild sailing on The Love Boat (1981)
Showing off his assets to Angela Landsbury on Murder She Wrote: Lovers and Other Killers (1984)
Take Two (1988)