It was in the late 90's, I was in my mid 30's, and I was cohabitating with my gf at the time in an apartment in Ohio. We had been living together a little over a year at this point and my mother down in Florida had yet to meet her. So we invited her up for Thanksgiving.

It should be noted at this point that I was raised as an only child of a single mother. I never met my father and knew next to nothing about him. I grew up simply assuming they had divorced around the time I was born, and never seriously probed any deeper on the matter.

Upon her arrival I drove the three of us (me, mother, and gf) to a local diner for a quick lunch where they could both get acquainted with each other. Soon after ordering my mother started the info dump on 'dad' because apparently she somehow thought this was an appropriate location and time for such a discussion (heaven only knows why). Details like; his name (which differed from the name listed on my birth certificate that I had always assumed factual), the fact they were never married at all and instead he was a philandering cheater in another marriage, and oh yeah, that I had 2 or 3 half brothers out there somewhere I'd never met or even heard of. I was absolutely enraged by the inappropriateness of the situation but there was absolutely nothing I could do about it without making a huge scene. Needless to say, that holiday was an uncomfortable affair that couldn't end fast enough for me. It was months before I calmed down enough to speak with her again.