Hot Wheels Drive Me Up The Wall!

Just before Big Boys birthday we changed the way that his room looked and with moving some things around we had to take down the Hot Wheels Wall Track that Top Ender had put up for him before Christmas. We knew that we wanted to put it back up because Big Boy really loved having the cars on his wall and it's much easier not having to put the track together each time he wants to play as it's just there on his wall. The box has been in my room for a few weeks now and so when BB saw it this past weekend he was finally not able to handle it any more and very politely (no really he said with a cherry on top and everything) asked Daddy to help him put it up on his wall. Of course Daddy agreed and together they put up the poster and the track on the only spare wall in BB's bedroom.

BB is over the moon, he loves making the cars go through the booster and then having them zoom around the rest of the track. So far BB has been very good and hasn't been playing with his cars when he should be in bed, going to sleep... how long should we give it before we catch him out?