We could have adventure stories about bad boys who turn their lives around through positive experiences, like a bad boy who discovers his love for art and uses it to better his community.
The bad boy is a hacker. He uses his skills to break into computer systems just for the thrill of it, not for any malicious intent really. But then he gets targeted by a real cyber - criminal who wants to frame him for a major cyber - crime. He has to use his hacking skills to clear his name and in the process, he teams up with a group of ethical hackers and starts to use his abilities for good.
One idea could be a bad boy who is constantly getting into trouble at school. He skips classes, plays pranks on teachers, but deep down he has a good heart and is just acting out because of family issues at home, like his parents being too strict or not giving him enough attention.
The main character is usually someone who is a bit more on the 'good' side, perhaps a bit naive or sheltered. And then there's the 'bad boy' character. He could be a rebel, someone who doesn't follow the rules, maybe has a tough exterior, like a leather - jacket - wearing type with a motorcycle. There might also be side characters who are friends or family of the main character, who either oppose or support the relationship.
Ending a relationship with a bad boy can be tricky. You need to be prepared. Plan what you're going to say in advance. Maybe write it down if that helps. When you talk to him, don't let his bad - boy attitude intimidate you. If he gets angry or tries to make you feel guilty, remember that it's your life and your decision. You can also consider gradually reducing the time you spend with him before the final break - up talk. This can make the transition a bit easier for both of you, but still be clear that the relationship is over.
Perhaps he has a crush on the girl and doesn't know how to express it in a proper way. But this is still a very wrong way to get someone's attention. He may have thought that by stealing the bra, he could create some sort of connection or stir up emotions, but it's completely unethical.