Can we still trust our partners??

1) Friend's boyfriend promise that he won't cheat on her again.. yet i bumped into him with another girl recently..

2) Friend's boyfriend sweet talk to other girls and date them out secretly.

3) Friend has a no-string-attach relationship with others when he is attached.

4) Friend told other girl tt she is better than his girlfriend.

5) Friend told other girl tt he likes her when he alrdy has a girlfriend.