I have tons of former ones. I'm avoiding a present one just for that reason.
1. When someone I'm dating confuses "discussion" with "unhealthy argument". There is a large difference, one is healthy and constructive, and one is destructive.
2. Confusing criticism with being cruel. Again, while you may not enjoy criticism, it is made to be constructive and helpful.
3. The "I understand..." thing. I tend to understand a lot of negative situations and the emotions that go with it, because I've been through a ton of various negative situations. However, when someone who's never been through a certain situation, and has no clue about it at all tells me they "understand" it does nothing but irritate me.
4. When my lover gets worn out far before I'm done.

It drives me mad and makes me wish there was a circuit of them or something.
5. When they rearrange my stuff. MY stuff goes where I put it, because it is MINE. If I use it, I want it where I want it, so I can use it in an efficient manner. If YOU put it in the manner that makes the most sense to YOU, it's no longer efficient and conveniant for ME.
6. When they tease me, and then get upset when I decide to get even. It goes both ways. No starting something you aren't prepared to finish.
7. Saying "Well if you don't know, then I'm not going to tell you." That, is like a pilot falling asleep on the little stick thingy that keeps his plane in the air. If something's wrong, and someone asks to be informed on what is going on, and you don't tell him, it's your own fault if it continues.
8. Wearing my clothes. I don't put on your clothes, and if you put mine on, I own whatever's inside them until they come off.
9. Blaming me for keeping you up all night after having dealt with being teased horribly all day while I allow you to do your work and not get even with you for it. It's your own fault for not getting any sleep in that case!
10. Complaing that "we" never do anything "you" want to do, when everytime we go to do anything I ask what it is "you" want to do.
I think I'll stop at 10...