Heroine sleeps with hero on his bachelor party

[Sarah]

Hero meets heroine at a bar(his bachelor party). His friends arrange her and she sleeps with him for cash and leaves morning later he finds she is a virgin and feels sorry. Later they meet again and hero's friend helps her knowing she is innocent but hero also pursues her. She thinks he wants her as his mistress because he already has a fiance and she finds herself in a tangle between his friend and him. She chooses his friend but later they come together.