Granted, sometimes I do it absentmindedly. When resting my hand on your arm or your knee, before I know it, I'll find myself petting you.
Like many things, sometimes I do it just because you tell me too. With a crook of your finger, I follow you to the bedroom. When you strip down and lay on your stomach on the bed, I do what is expected of me. Gladly. Sometimes it leads you to relax. Sometimes it leads to sex or some other play. But either way, I am not doing it because I'm nice.
At first, it was the one time we were just two people, when you were just my boyfriend not Master or Daddy or Sir. It disarms you. It's the one time I can feel somewhat in control, even if you initiate it. Very quickly, you can't think enough to give orders. I set my own pace, decide what to touch and when. When you haven't initiated it, I know that a minute of stroking your back through your shirt will lead to it coming off and a few passes of my fingers under the waistband of your boxer briefs will lead to them coming off as well. It shows me that I can do to you what I know you so easily do to me.
But ultimately, I do it simply because it turns me on. Because I feel the little, and not so little, noises you make touch something deep inside me. Because you can make my breath stop when your breath becomes shorter and faster as I get closer and closer to particularly sensitive spots. Because it makes me wet to feel you start to tremble when I stay in particular spots just a bit too long. Because I get to see how long I can go just touching you, when I know that just a few well placed kisses will get me a whole new set of things I yearn for. Believe me, I definitely do it for me.
But I don't do it because I'm nice. When it's just you and I, there are very few things I do because I'm nice. I would have thought you would have known that by now.
And don't even get me started on why I do it to her...