I remember watching this 2012 or 2013 trailer on youtube about a woman who has a perfect life and perfect husband. I believe she is a model. This younger woman become interested in her life, and wants to replace her. The trailer had a graphic sex scene where the older woman wakes up to her husband groaning and having sex with the younger woman in the same bed while she was asleep. The younger woman looks at her and asked her if she wanted in on it.