Do you want to jump?

We've had the trampoline for almost a year now, and still Tyler's favorite thing to do is jump. Whenever he sees me, the first thing is says is, "Do you want to jump?" When I get on there with them, they make me chase them, and play games. They don't give me a moments rest for at least 20 minutes. Any less time is "too short." Tyler always does "falling rocks," which means he lands on his bum and expects me to fall over each time he does it.