You shouldn't sleep with someone who is already married.
Justin runs into his friend Shana from high school who had a crush on him, and finds out she's married.
Justin wants to take some time to reconnect with Shana.
Justin has a short chat with Shana at the store, learning about her kids and current job, then hugs her and says goodbye.
Justin invites Shana out for drinks, and has sex with her in a motel after they get drunk.
Shana goes home to her husband, mentions meeting an old friend, and continues her life.
Shana commits infidelity and feels guilty, and her marriage suffers moving forward.