I’m going to go with it wasn’t an accident at all. It would be pretty tricky to accidentally text you instead of Bob since your names aren’t even close to each other alphabetically. So either she isn’t very bright, or she did it on purpose. Girls like drama, so maybe she did this to initiate a breakup so she can date someone else. Or maybe one of her friends/jealous friend did this to make you angry and break up with her. What I would do is ask her about it again, tell her you don’t believe her / trust her answer and ask if its ok to check her phone calls/text messages like whitestallion said. If she says she doesn’t want you to check it, then she is hiding something and then you should just end it without even checking. Hopefully she lets you check it and that will give you the assurance that she isn’t cheating. Then, after you check it and everything is ok, you have to apologize for not trusting her, and take her out to dinner or something nice. If all else fails.....PIITB.