Moving Tail to the Side, Yearling Colt??

[Englishcowgirl91]

So I was grooming my yearling this eve and it is the first time he has done this. So I was brushing him and he started moving his tail to the side and holding it there. I have never seen him do this before and so I just thought maybe he likes what I am doing, he almost looked like he was going to turn around and scratch hind leg but tail was tensed up to the side only when I started brushing him.
It is only now that I started thinking he was in pain or it was some muscle thing?

Is this something good/normal or is it something that pro needs to look at?

I moved out the way to see if he would scratch but he didn't.

 

[Flowerofthefen]

My horses get in all sorts of positions when scratch their tails!! Definitely enjoyment!!

 

[Englishcowgirl91]

My horses get in all sorts of positions when scratch their tails!! Definitely enjoyment!!

Ah yes I did wonder. I was brushing along his back and then I was worried his back was sore. But hopefully enjoyment

 

[Mrs. Jingle]

My old mare goes into a stretchy, bendy, gurning faced, athletic, squirming, tail swishing and ecstatic heap when I groom certain parts of her body, she always has done. The grooming ecstasy moves she makes now in her golden age are far more athletic and supple than she ever was able to do when she was still ridden.