All In The Family On Craigslist

This week's Dear Prudence advice column in Slate deals with a bisexual married man who says his own (also opposite-married) father-in-law tried to hook-up with him on Craigslist. His letter reads, in part:

The issue is, I am bi-sexual and have known so for quite some time. My quandary is, about a month ago I responded to a posting on Craigslist. It was from an older gentleman who, like myself, is bi and was looking for some discreet fun. In responding to the ad, I sent a faceless/headless picture of myself without a shirt on. He responded back to me with some pictures that were a bit more graphic and a phone number. Upon seeing the number, I became immediately undone. It was the cell phone number of my wife's dad—my father-in-law! Once I realized it was him, I never responded back to him. I received several e-mails subsequently asking me what was going on and if I was still interested. However, not only did he e-mail me from his personal e-mail address, stupidly, he used the joint one with my mother-in-law. Fast-forward a few weeks. My mother-in-law was checking e-mail and somehow found the exchange between my father-in-law and myself. Obviously, and justifiably, she has become hysterical. She found the e-mail that I sent to him (from an anonymous e-mail address) that had my picture. It gets worse; she told my wife and her sister and brother, and they are trying to figure out who this guy is who "seduced" dad.

Some of the column's commenters are calling BS on the entire letter, but the discussion on bisexuality and fidelity is worthwhile.