According to Mark [The Gospel of Love]

Neurosurgeon Mark Finley has a deep, dark secret. No, it's not that he's a dominant who likes to mix pain with pleasure; it's that he's in love with his best friend's wife. Mark is wracked with guilt when his friend dies on his operating table, but when Allison begs him to make love to her, no power can stop him. But he swears it's a one-time event. And it is until Allison turns up Mark's favorite club. Mark can't let another Dom have her, but he can't have her either. Or can he?