Was at the park on Sunday alone with DS (5.3) and DD (2.9). DS has his bike with him, he is very proud he has just learnt to ride without stabilisers. In the playground we met a little friend from school also with his bike. It turned out the other boy's mother was on the other side of the park, not in the playground, out of site sunbathing on a rug. The boys wanted to zoom backwards and forwards between the other mum and the playground on their own.What do others think of this, I wasn't sure if this was ok or not realy, but they are fast on their bikes and very difficult to keep in site as I had DD with me. DS is my first so this is unchartered water. What do others think?