Yeah bud. Liking someone doesnt give u the authority to be a dick and invade her privacy by trying to hamper their relationship. Sure, felix could be a manipulative and toxic guy, but u gotta remember that it's your friend's choice to be with whoever they like. The only thing I'm getting from reading this post is that you are the one acting like a walking red flag. I'm 19 now so I've been in your shoes only recently but going through someone's phone and texting other people behind their backs isn't something I wouldn't even contemplate doing.