Young couple Samantha and James were virgins when they met, but James is shocked to learn that his wife is more sexually experienced than he first thought. He starts thinking of his wife with other men, and for some reason it turns him on!

James convinces the playful but innocent Samantha to explore her sexual urges while on a girls' trip to Mexico with her best friend, Jenny. Samantha and James share their perspectives in a series of emails as they navigate the joys and perils of a newly-open relationship. Will the experiment tear Samantha and James apart, or will their forever-love endure?

Samantha's Diary is a mature yet playful exploration of thoughts, emotions, sensations and relationships as a husband discovers his kinky side and a wife discovers her naughty one.