If I Were You (2012)

This movie was recommended to me by my sister-in-law, and it was a good choice.  I have been trying to stay away from things that are too serious or too deep, and this is neither of those, without being just another romantic comedy.
The set up is one you have heard before.  Husband is having an affair with a young and beautiful woman, and his wife finds out.  She finds out he is working late, so she stops at their favorite cafe to get him a piece of his favorite cake to surprise him when he comes home, only she is the one surprised, because he is there snuggling with said mistress.  She calls him again, hoping he won't answer the phone, that she is mistaken, but she is not.  The husband gets spooked, thinks his wife suspects something, and leaves, with mistress in tow.  She encourages him to end it, and he tells her what we all know, which is that he has not intention of doing so.  He likes to have that proverbial cake and eat it too.
What happens next is the twist.  The wife follows the mistress, supports her in her misery, and they become allies of sorts, and eventually friends.  It is a quirky, funny, likable movie that goes places you wouldn't expect, and that are quite enjoyable.