Mixed message about adultery
On one hand they're telling you it's not okay to cheat on your spouse. Mel, Burt Lancaster's character, is stuck in a loveless marriage with his wife and is in love with Tanya. But no matter how he feels, he won't stray. They're showing you it's not okay to cheat. Mel does end up with Tanya, but only after his marriage is over.
Then, on the other hand, we have Vern, Dino's character, who is married to a nice wife, but he has no problem cheating on his wife with Gwen. In the end, Vern learns that Gwen is pregnant with his child. He gets to the airport and doesn't even look for his wife, who is noticeably concerned, and he goes off to the hospital with Gwen to live happily ever after. I don't get it. They say it's not okay and then that it is okay. I found it funny.