Wanting to do phsyical tasks for girls?

So Im this girls slave i know and shes my master....its not really serious though because were only 13...just for fun..but tonight shes asked me to do stuff like push ups and climb a tree over txt and i did it...well cuz i was bored and i am her slave, but i really enjoyed doing them for her and wanna do more tasks for her...is this bad? Like bad that i enjoy doing this for her and acutally love the idea of being her slave?