HELP!!!

I need some advice! My boyfriend is always into pleasing me, making my body feel good during sex, but when it comes to me sucking his dick or me taking the lead in sex, I seem uninterested. He even noticed that I treat pleasing him like a chore. Sex is always great for me, always fun, and I almost always climax. We've been together almost 4 years, and it gets better every day. But how can I get more interested in giving him head? What tips do you have? What is it about giving him head that makes you satisfied in watching his glorious nut?