Flight Attendant reported another Flight Attendant did not allow a door to be disarmed and interfered in a way which could have resulted in an inadvertent escape slide deployment.

Narrative

I worked flight ZZZ1-ZZZ; aft galley 2L door and my ZZZ base co worker; FA A was beverage cart assigned door 2R. We had a 3rd FA; FA B. FA C working with us on aft galley. Since from the beginning till the end of the flight FA B picked on us for everything; stating all we did was wrong. Way too many times. But; the most concerning; was the way she overstepped us on door closure and on arrival as well. On door closure; me and FA A armed the doors and crossed checked. FA B immediately; stepped over and stated that was incorrect and proceeded to disarm our doors; and did on her way. We both got surprised with that behavior; and; we re trying to make it thru; this X hr XX minutes flight time to ZZZ with no problems. But; the worse was about to come; upon arrival in ZZZ; FA A disarmed her door; and I proceeded to disarm my 2L door; I had difficulty to disarm because the girt bar was stuck in brackets; due to the way she armed my door on closure. FA B did not let me disarm; stepped over; again stating 'I'm going to show you how to disarm your door'; I confronted her; saying please; stop touching my door; I've been flying for 10 years; and I've never had any incident related to safety or something else. She replied ' you stop in been overreacting '. My concern about her touching my door; could cause a slide deployment; and it's my responsibility to disarm my door. It really scared me. I can say that; I felt very uncomfortable; working with a coworker constantly telling us; we are wrong; and overstepping her duties; all the way to ZZZ.