I like to think of this as a teasing (but not necessarily cheating) scenario where a male friend's wife or fiancee (or other unattainable female acquaintance) is naturally beautifying herself in front of you, while you're a captive audience. She's conveniently "forgotten" to wear undergarments, but she doesn't seek to put any on, and it would be rude if you got up and went into another room! You've got to let her entertain you for the sake of human decency (of which I have little) and "platonic" conversation, all while hiding your erection from her man!
