The 20-year-old singer-actress, who dumped the Canadian star in January after two tumultuous years together, is amused by his immature actions which included arriving two hours late to a concert and threatening a photographer in London earlier this week, reported Hollywood Life.
"Selena has kept an eye on Justin in the news and just laughed and laughed. She doesn't give a shit anymore. Justin is crazy and she doesn't want to be his mom anymore.
"She feels so free and loves hanging out with her girlfriends. He's weird and she doesn't find his behaviour hot or anything. She just wants a man who has his shit together, and not a weird boy," said an insider.