Update

Yesterday B had 4 'accidents', and only one today, so I guess that's an improvement. They usually happen the minute I go to the toilet or start making dinner, or if I leave him after playing together.

I asked him what he wanted to do today and he said he wanted to go look at trains, so we went to a park near a train line where he was in his element. I'm hoping the good run around has done him the world of good. We'll just have to see what tomorrow brings when it's back to the 3 of us...

Thanks for all the encouragement, it really means a lot.