Warm and kind NTR about your girlfriend getting it on with a younger guy, since she knows all about your cuckoldry fetish. Yes, this is a soft masochism story about pure love, and cheating confessions.
You have a flirty lovey relationship with your childhood friend = girlfriend. However, it turns out that her mother is in need of some love. A lot of love in fact... and she comes knocking on the door of your pants while her daughter sleeps.