Once again, you are right - my son rides bikes and i worry, but he is an adult and can make the choice and although he has a car licence, he prefers bikes.
I do not have a pro-bike stance and I understand the OP point of view, we are talking about a ten year old here. So I wholeheartedly agree with you HRH but to be fair i also agree with Dukey, I can see both sides.
However, once the OP has made her feelings clear, what more can she do if her ex choses to take their son on the back of his bike? She can either frighten the boy witless about what could happen or as Dukey says trust that whatever else is going on in her and her ex''s life, that they both love their son more than anything else and if he takes the lad on the back, he has to take total responsibility for his safety and have his eyes out on stalks, keep to low speeds and never, ever, muck about. If she cannot trust him to do this, the only right thing she can do is to take advice on how to legally stop him from being able to get on the bike if that is possible.
I hope that the OP doesn''t think that her post has been hijacked, bikes are an emotive subject and she wanted a legal answer to a situation rather than whether bikes are good or not.
Sorry Pete - last bit wasn''t meant to sound critical. I''d written more and then thought twice about it....deleted the rest and then left that bit by mistake....it probably does help poster that she knows that you understand.)