Asklemmy

So, I am a 21 year old male but when I was a kid about 8 maybe 9 l had this friend from church also male, who is a couple years younger than me. One day were sitting somewhere and he mentioned something about wanting to touch my butt, and he tried to grab it. And then I think I was playing with something and dropped it so I reached down to pick it up and he smacked me like four times rapidly. He seemed to find it amusing. I thought it was kind of weird for a bit but eventually I forgot about it and we remained cool friends. He hasn't acted that way since and this was over a decade ago. I know his grandma said he used to have a problem with seizures as a kid. He still goes to the church but not as often because he works now. Like I said, I hadn't even thought about it until like a month ago when I read an article about a celebrity who had been sexually abused as a kid. And it triggered me for some reason and has been kind of bothering me. I just wanted to know if this was an assault or just inappropriate childhood behavior.