She Came Back.

Kate (Halle Hayes) and Rick (Small Hands) look like a perfectly dull married couple, but someone from Kate's past is about to change everything. One day, Jen (Aila Donovan) shows up at Kate's door... several years after being in a relationship with Kate and disappearing without a trace one night. Kate is torn between her loyalty to Rick and her unresolved feelings for the mysterious Jen, eventually choosing to have sex with her. Her world now turned upside-down, Kate has to find out what Jen is doing back in her life, while hiding her guilt from her husband (who's far from an innocent victim in all this). Is Jen a friend or does she have something more devious in mind for the couple?