Comedy and fantasy movie - mysterious castle, scary altar and stone griffins

[wositelec]

I'm looking for a comedy movie (between 1980 - 2000 max). A marriage (they aren't too young) with their friend on vacation, perhaps some island or small sleepy town with a castle. The woman is appalled that her husband doesn't remember their wedding anniversary, so she leaves the hotel on her own and explores the town or an island. Then, a strange guy notices her (he is an elderly man with long gray hair) and he offers her a walk and buys her a red dress. I remember he tells her he lives in a castle and invites her there. He gets her drunk or gives her something and carries her to some sacrificial altar, at this her husband rushes in and on some tower, he fights an evil man. Then, he brings to life the stone griffins (or dragons) that decorate the tower. Everything ends well and the final scene as how all three of the wife, husband and their friend sit outside the hotel and ride away on donkeys is how the film ends.

One from actors could be similar to Danny DeVito.