What's wrong with me?

So I'm in a ldr with my best friend. We've been close for 3 years and just started dating 4 months ago. When we're together we are both pretty clingy and not shy about getting it on. Haha I'm usually in the mood like every day I spend with him. However when we are apart obviously there is not a whole lot of sexy time. We only get to FT like twice maybe 3 times a week. HERES THE THING. I'm not into the whole pleasuring myself thing very much. Like I'll do it but it's very rare. But sometimes when we FT he will ask me to show him something or do something for him and unless I'm in the mood, I feel so offended. I don't even know why?? Is that weird? He doesn't even ask that often. Why do I feel offended? Is he doing something wrong?