mum you love me right? and you like seeing me happy right? well... guess what would make me very very happy, some lovely new skis. and we all know skiing is a healthy outdoor activity which keeps me fit and stops me from getting fat. and currently my bummed out old skis are preventing me from skiing. (make some tech thing up which'll baffle her -unless she knows skis- as to why your skis are buggered, i used to do it all the time with bmx stuff)
then hug her