Two stepmoms, Rachael Cavalli and Aiden Ashley, are enjoying a rare romantic night alone while their stepdaughter, Lily Larimar, is away at a slumber party. They begin making out, but are interrupted by a door slamming. Lily barges in, looking upset and saying that she left the slumber party after her friends teased her for not knowing much about sex. The stepmoms are concerned and sympathetic.
Lily then notices the romantic setting in the stepmoms' room, but seems to be clueless about what it's all for. Rachael and Aiden realize they've sheltered Lily too much, and start to finally talk to her about sex. Thanks to their explanation, Lily realizes that Rachael and Aiden were about to have sex right before she walked in on them.
Lily begs them to show her how it's done, so that she won't be embarrassed in front of her friends anymore. Rachael and Aiden are surprised but don't want Lily to be embarrassed anymore, so they give in, having sex while Lily watches. Eventually, Lily asks if she can join in, saying it's the best way for her to learn. Rachael and Aiden agree to it, leading to a loving and educational family threesome!