Using them without asking permission is a bit of a liberty, to put it mildly.未经同意擅自使用这些东西，说得轻一些，有点失礼。Don't her parents mind her making free with their house while they're on holiday?难道她的父母就不介意她在他们度假时擅自使用他们的房子吗？I don't like the cool way you used my bicycle without my permission.我不喜欢你这种擅自使用我的脚踏车的自作主张的行为。