DS 7 months dry and now too lazy to go!!! help!!!

[hancan]

How do i re ignite his enthusiasm???

He potty trained at 2 years old in 3 weeks flat. He stayed dry at night amazingly so we went with it. We used sweetie rewards. He has been brilliant for 7 months. At nursery he was even managing to take himself to pee in the toilet so we took away potties and he does everything in the loo. He is pleased to go but prefers us to watch. So then i tried offering reward if he went all by himself and we applaud him and praise him on his return. This is harder and he is less keen. He has a younger brother who has just started crawling. Now its the summer hols. no nursery. just me and his brother. and maybe its attention related but he just keeps holding it in. refusing to go and then i get cross coz i see wet pants and then we march to the loo to get the wee in...and its all going wrong!!!!

i hate getting cross. i just feel so frustrated and am so busy with the two of them. i wasn't expecting backward steps....

any ideas?????????