Not sure how to feel....

So me and my dude have been together for a very long time and it something new has been happening that I don't know what to think. During a certain job that I do I have noticed that my guy will move his hands to his other side. Now I don't know exactly what they are doing back there but I have an imagination. He has requested during sex before many times that I use my hands back there and it's nothing against him but no, and I repeat no no no my hands will not be doing any job back there. It's just not for me, period. Nope not happening. Does anyone else's guy venture into there own back end? Is this a thing?