I used to just ignore ex too, it wasn't worth the hassle.
Mind you, if he annoyed me I used to pour all his milk away (I rarely use milk so never had any in) and just leave half an inch in the bottom. Or run all the hot water away.
We had this 'hilarious' argument - it was a weekday, we were both home (he works at home, does fuck all most of the time, I had some time off, but he didn't know that). I was having a terrible morning, my sister had been admitted to hospital and had been presenting as very depressed and I was frantic thinking she had self-harmed but couldn't get hold of her/anyone. Then I did and it calmed down - I was due to leave to go away for a few days to a festival.
He was pottering here and there in the house. I went out the side door to load my car, came back in, locked side door behind me (it was something we always argued about, how he thought it was fine to leave all the doors unlocked even wide open, and not be in that room).
I then went to ask a neighbour to feed the cat as I knew ex was away for one of the days too. I saw the patio door was wide open, so I pulled it shut and locked it. I went out, locking the front door behind me, which is what you do when you leave the house - assumed ex was in his bedroom 'working' wanking.
Saw neighbour for what must have been about 6 minutes. Didn't even have a cup of tea. My car was on the drive.
When I came out, neighbour came out with me as she had an errand (hence me not staying long) and ex was up a ladder climbing in the bedroom window. I looked at my phone and there was a text from him calling me all the names under the sun and saying 'I suppose you think it's funny, don't think I don't know you locked me out on purpose, you bitch' etc.
Neighbour was like 
I was like 
Why he hadn't texted to ask how long I was going to be, I have no idea. Why he didn't pop over to said neighbour and say "I seem to be locked out, you have the spare key, could I have it?" I also have no idea. I guess to him it felt better to act the halfarsed victim.
When I got in he launched an attack on me (verbal). He said he was in the garage (the doors weren't open, he usually has the door open when he is in there - all the house doors were wide open though!) and that he had heard me put stuff in my car so I should have heard him in the garage - no idea what the fuck he was doing in there that I was supposed to hear, but I didn't. I said "well, maybe I couldn't hear you over all the noise I was making putting my bags in the car" (which is obviously not noisy at all).
I asked where he thought I might have gone, without my car, that would take more than a few minutes (we lived in a village, I knew about three people, could maybe have gone to the village shop but that didn't make much sense given I was about to leave).
He yelled at me about why was I even still there, when was I moving out etc etc.
I yelled back that I had found his adverts on sex sites and that I now knew he'd been doing that for 12 years which was before he left his ex wife and when his son was 5 and that he was disgusting and should be ashamed of himself. To be fair, that actually did shut him up.
:)