Need step-son advice

I was reading up on the montessori method and it reminded me that you should model "the right thing to do" with your children.

Now my step son is 7 and has a lot of wee accidents, but we just tell him to get changed. Therefore its just been excused a "boys" bladder (his dad has a terrible bladder). But realised using the toilet is behaviour you can model?

It got me thinking and it seems now its very predictable and his reasons are the same everytime. He instantly shuts off into "im in trouble mode" but I don't see how it can be attention if we literally say "ok" and he gets changed?

He also gets plenty of attention and 1:1 time with his dad!! Though he only visits at weekends.

On sunday he made his own breakfast, he usually is encouraged to, but I was ill so stayed in bed and my husband was in the process of getting up, but he asked us to join and he said we would.

So alone making his breakfast he races upstairs because he has spilled water, fair enough, told him how to clean it up.

Moments later back up again, he had spilled milk!! Again went down told him how to clean it up.

Then hubby finally went down, he had spilled again and not told us? Ss cleaned it up then went and played. I wanted to address what happened but hubby was fine to leave it as he was punished by cleaning it up? Its bothering me though, how he spilled something 3 times when he wanted us downstairs?

Im 30 weeks pregnant and we ask him often how he feels about it etc, he is always talking to bump and kissing it and feeling the kicks, so I don't want to say its the pregnancy?

He is a cuddly boy and is almost always having cuddles from us and is otherwise a really well behaved 7 year old and I just really can't put my finger on it and somethings really bothering me!