I watched a movie in 2009-ish, on tv (so it had to be out for some time because I doubt I had HBO). It was about a women that finds out her husband is cheating on her with a married women. She knows the two of them are going to a cabin, so she finds the women’s husband and brings him to the cabin to discover it himself hoping he kills her husband for sleeping with his wife. All I can remember is that it was a twist ending… any idea what it was called??