Awkward Moment

So the other day I was giving oral to my boyfriend. He has nutted and I swallowed. (That time he didn't know he did.) Then he tapped me and said he was about to nutt. So I keep doing because I was just thinking he was getting a second nutt off, but it wasn't he had peed. I gagged and he was worried because he thought I threw up. I had told him what happened and he was nervous because he thought I was mad, but I wasn't. We both laughed about it and I instantly brushed my teeth. He said it was a feeling he never had before and it was great. I was just curious to see if this ever happened to anyone else, or if anyone knows why this took place.