Warning- Graphic potty training story ahead

So I have been potty training Seb this month. It is a bit early perhaps (he will be three in September) but summertime is the best time to do it, and I really didn't want to wait another year.
He has actually been doing great- at least with the potty part. The other part, not so much. He has managed to evade my notice every single day for two weeks to do his business in a private corner somewhere, and I was getting pretty sick and tired of hearing James announce that Seb had pooped on the rug again. So tonight we were determined. Steve put him on his potty seat and I told him he was not getting up until he had done his business in the right location.
Then I went off to do something or other that needed doing. Actually, I must be honest here- I was watching some Netflix. I know, nice mothering right? I was planning on checking on him in a moment of course, just as soon as the next scene was over. Well, I heard some crying, but I figured he could sit it out for a minute or two. The crying got louder and Steve went to check. I heard him start to laugh, which in my opinion, is never a good sign when potty training is involved.
I peeked around the door and was startled to see Etienne standing in front of Seb, who was happily sitting on the toilet still. Etienne was weeping copiously and it took me a minute to realize that he had pooped all over the floor. Poor baby. He had run to the toilet in an emergency, only to find his little brother in the way, and his mother totally ignoring his cries for help. He was so embarrassed he had tried to clean it up himself which only made things much worse. I will spare you a picture.
Sigh. I know these days will be over before I know it, but when they are happening, they seem like the days that never end. Sorry if this has grossed anyone out, but I had to vent somewhere and I did warn you.