As for why I don't like sex in my stories. Oversaturation. If I want to see sex, I'll just have to switch a few tv channels to see a woman performing felatio on a hot dog in order to sell a car insurance. I'm just sick of it.
Mind, this thread got derailed hard. I'd really like to know if there are some people that know of instances where a man ends a relationship with a woman for sane and non-douchey reasons...and not because of the woman trying to kill him, or such.