When two humans have lived together for many years it usually happens that each has tones of vice and expressions of face which are almost unendurably irritating to the other.
The Screwtape Letters – C. S. Lewis (1942)
They say that the more you live with someone the more you get to understand about them, which often uncovers things that you don’t like. The little traits and habits that drive you mad, that you find impossibly annoying, that drive you mad.
I think the key is to tell then … not in a nasty way but just let them know the thing(s) they do that cause this reaction in you. Easier said than done, granted but at least by alerting them to the issue if (or when) you do finally lose your rag it won’t be a complete out of the blue for the other person. On the other hand, if you do explain the situation and how much it affects you and they simply carry-on doing it then that is a different ball-game. There are two schools of thought here, one is that it is such an ingrained habit that they will find it almost impossible to stop doing, or that they just don’t care how you feel and will continue to do it anyway.
Telling the difference between the two is tricky and depends a lot on your frame of mind at the time. If you are that way out then you might be more inclined to tolerate it but if there are contributing factors affecting your judgement the situation could escalate.
Unfortunately, there is often is no happy medium but maybe compromise is good place to start.