Fetish developing?

[New and Shy]

Recently, while having sex with my wife, she reached down and was rubbing my thigh, balls, and butt. Eventually, she was rubbing her fingers between my scrotum and hole. Next, she had her finger almost in my hole. I was paralyzed with pleasure. Usually when something feels really good, I can't help it and I explode in orgasm, but this was different. It felt so good I felt like melting. I found myself thrusting to match her finger motions so that on my outward thrust I was almost sitting on her finger. I loved it!!! However, the next time we had sex, she didn't touch me at all, not my hole, not my butt, not my leg, not my balls, nothing. I found it difficult to orgasm because I kept waiting for her to do it again. I don't want to ask for it because I want sex and everything involved in it to be spontaneous. Because I had difficulty climaxing I wonder if I am developing a fetish? All I know is I want it again!!!!