Club Paradise
I don't remember a thing about his movie apart from it being something like a 1980s teen sex comedy but with more serious actors. I also didn't realise Harold Ramis directed it or that it was a Saturday Night Live, Second City pet project for all concerned. Williams plays a retiree who falls in with a property owner on an idyllic Caribbean island and joins his scheme to launch a resort for rich Westerners.
Williams and Moranis both play against type uncomfortably by not, respectively, not playing up Williams' mugging persona or Moranis' nerd persona, and the whole thing falls unsatisfyingly flat.