Your friend has just broke up with Anna and you get roped in to go and collect his stuff. You know she is going to be pissed, but you always got on with her so its not such a big deal.
She invites you in for coffee and confesses that your mate and her used to argue over you, he thought Anna had a thing for you.
You fully intend on leaving here with his stuff and your relationship with your own girlfriend in tact. Thats your intentions, but in reality you cannot resist her.