@Watchkeys I have reported to 3 different managers over the last couple of years.
Manager 1 said I can't do anything unless you raise a formal complaint (gambling on me not doing so)
Manager 2 I emailed to report behaviour but said I don't want you to do anything as it might escalate if the person knows I have reported.
Manager 3 (I told her directly that I felt this is bullying and I am not far from a formal complaint) had us both in a meeting where the onus was placed on both of us to cooperate and to come up with positive statements about each other. And for me to give the person direct feedback on behaviour.
The person wanted me to admit that I had hurt her feelings and I said I was sorry their feelings were hurt however I had not intended anything like that and it was their interpretation (in fact they were the one who blew a gasket in a rage about something some tiny it is laughable).
I did say to the manager I am not having 1:1's with the person to challenge them in private as it just becomes a forum for them to tear a strip off me without witnesses.
Uneasy truce right now but I do know there will be a next time. It isn't just me this happens to but the other members of team say its just the person 'being moody' and 'just walk away'.
Manager says to come to her any time something kicks off - I did explain its usually a trail of small incidents (which seem petty to report - micro aggressions really which can be hard to pinpoint as they are tone of voice like sarcasm which person may defend by saying its how I interpreted - hard to prove) which inevitably lead to something bigger after a lead in of say 5 or 6 weeks. Previous incidents have involved: light switches, windows, cardigans, not wanting to read something the ex had sent the person (long back story but abusive relationship). Its all nonsense but is made a huge thing of if anyone dares to challenge or is perceived to.
It often catches me off guard when the person blows up - blindsides me. Though last time I did tell them exactly what it makes me think/feel. It's eggshells all the time, but the job is one I love and have been in for ages - fits well with DC and DH work etc Would be nigh on impossible to find as good a situation where we live.
Its the same for the other person too so they will probably only leave due to old age. I dread more years to come of this situation.