Quote from the article

Under U.S. law, people have a right to an expectation of privacy, even with close loved ones, Judge Keith Cutler explains. This means that if he hands you his phone and shows you something or leaves his screen unlocked and open where you can obviously see it, he is not expecting it to stay private. Other than that, you have to ask first. It can be frustrating to be with someone who will share a toothbrush with you but not their phone, but ultimately that's their call to make. (And it's your call to decide if this is something you can live with in a relationship.)

READ AND UNDERSTAND LOGICALLY.

楼主的情况是，男方在开车，需要她帮忙在手机上查地图。她得到的准许是地图，不是短信历史。况且他俩只是一般性伴，连同居关系都没有。