Umm, you’re reformed? Someone’s face has a different look and you, an adult, aren’t sure if you can hang out with them, or you’re not sure you can control your own face, and you think this is so dire you need the advice of internet strangers? Sheesh. Do your friend a favor and leave this person alone. If you’re thst judgementsl about someone’s appearance and lack the maturity to manage yourself, you’re doing right by your “friend” by not polluting their world with your insecurities. Good people don’t do that to others. Good people don’t run screaming when someone has one different facial expression. Also, maybe seek some counseling for yourself to better understand what is causing you to react so strongly. Clearly the problem is with you, not your friend’s face or expression. Fix yourself and the problem is solved.