TL;DR at the end. Obligatory "technically" this happened yesterday, about 8 hours ago. So I (M27) went with my fiancée (F28) to her family's Christmas celebration. I get along great with her family and they like me because I treat her well and I can (usually) carry a conversation without being overbearing or boring. We all finish eatng Christmas dinner and queue the FU. We start talking about deserts that everyone brought or made, and we start talking about our favorite deserts. I said mine is pie, but the kind with Graham cracker crust and whipped cream / cream cheese filling and a fruit topping, usually strawberry or blueberry. One of the aunts mentions her favorite dessert was muffins. At this point I got bored with conversation for whatever reason, and started to disassociate and go on my own mental journey without really processing any outside information. A short amount of time passed, maybe a few minutes, but no more than 10 I think? And grandma (let's call her Annie) asked me which one I would like to have. This snapped me away from wherever I was going, and I stuttered for a moment as I tried to gather my surroundings. Uhh, well... I stammered as I tried to think of what we were talking about. The last thing I remembered from before I dissociated was muffins, so I thought that must be what the conversation is still about. It was not, but I thought it was and so I replied that I would really like a chocolate one. The look on everyone's face was a mix of confusion and light shock. Annie managed to stutter out s-sso you plan on adopting, you don't want kids of your own? And I just stared at her, not speaking, with a totally blank expression. I did not know how to explain to everyone that I thought we were still talking about muffins because I dissociated our of boredom and ADHD. My fiancée was looking at me with piercing eyes that said: fix this NOW or I will murder you when we get home. Eventually i apologized and said I was making a joke, since we talked about desserts beforehand. There was some laugher about it, and the night moved on. For anyone asking, no my fiancée did not murder me (yet), and we still plan on getting married.

TL;DR Was having a conversation about deserts with family (we are all white) when I dissociated, and during that time the conversation switched to babies. Unaware of this, I answered Chocolate to the question of which kind I prefer. Family was mortified and I had to answer some absurd questions to fix my FU.

Edit: grandma Annie was asking which gender of baby I would want, if I wanted a boy or girl. She had asked my fiancée, and my fiancée said a boy so Annie asked me which one I wanted.