2. I am all about forgive but never forget, so I would believe my guy but I would always have my eye open. Girls like to make up crap. She could have hit on your bf and he said no and she is salty. Some females are full of scorn no matter what.
3. Females are confusing and annoying at times, I know his because I am one lol. Sometimes we do passive aggressive crap for absolutely no reason, just to get an reaction. All I can say all you can do is talk to her and ask her if she is okay and then nonchalantly mention her tweet and ask her "if we are good'.