Define: Foot in mouth (I think. I'm not entirely sure I fully grasp the meaning of that phrase.)

I don't know what made me think about it, but today I remembered doing something really stupid at camp.

At the beginning of the summer, one of the counselors told us that his mom had passed away when he was really little, and his dad had remarried. At family camp, he was pointing out his brother and sister to Becca and I. Using my fine skills of observation, I pointed out that his siblings had blonde, almost white hair, while his was brown. "What happened to you?" I asked, having completely forgotten about what he'd said at the beginning of the summer.

And then I remembered.

I apologized profusely, and he didn't act upset, but I'm still not entirely sure if it bothered him. I felt super bad and embarrassed. And still do.