yes it can manifest into resentment and silent contempt
It can be if it festers within, makes you miserable or builds until it explodes
hiding anger never works, because it always gets to a point where it escalates and either immobilizes you completely or causes you to lash out in a rage, further causing harm to yourself and/or others.
That is a really covert question. Give the situation from all sides included, then perhaps you can get a proper answer.
No but I'm one of those who releases their anger on the spot and from experience that's not a good thing either... :/
Channeling it into something more constructive is better.
Eventually it will come out and that is worse.
Until you go to the batting cages.....