What seemingly small differences of opinion or practice were (or are) dealbreakers for you in dating? And what style or etiquette points do you live with or nag about in your relationship rather than walking away?

Closely related to katemmcoy's situation, before I met bf I went out a few times with a fellow whose footwear was either hiking boots or flip flops. Stains on his uniform of sweatshirts and cargo pants were no reason to retire the garment in question. The one time I invited him in for a cup of tea after a walk on the beach, he left a large amount of sand on the sofa and floor, and didn't offer to clean it up. I ignored his attempts at further contact.