Those are some selfish ass women guys!
When my wife and I were first dating and we started having sex, I'll admit I was a little selfish in bed. I ended up feeling a little guilty about it after a while. But early on she sat me down and told me that it takes time for her to come and ever since then I always try to last longer during sex or eat her out first beforehand and make sure she has her orgasm so she's satisfied. On top of that, I love watching her shake and moan while she's enjoying herself. I've made her scream at the top of her lungs only once since we've been married (she doesn't like to do it but she lost control that afternoon!) and it's one of my goals to figure out how to make her do it constantly!
Moral of the story, communication IS key.