Is AUTHOR wrong in the post ? POST : Hello there, first time posting here! Posting from phone so sorry if the format is a little weird.

TL;DR bottom

Now, to elaborate this, I(20F) got my boyfriend (21M) ,who we will call A, for Christmas a Nintendo white hoodie cause I knew how much he liked it and wanted one and he was really really happy with it. 

*Side note : he is still friends with his ex, who we will call B. They have the same friend group and sometimes hang out all of them, never just the two of them. At some point in their relationship B wanted to get 2 Nintendo hoodies, you know, to have couple matching clothes and stuff but they never got to. This was quite some time ago , not close to the period when they broke up.
Also, not many people know we are dating (including his ex), just our close friends. We're not hiding from anything but we don't feel that is neccesary to announce everyone that we're dating, or so to say.*

So last time they met he went with his hoodie and she asked him "When did you get the hoodie?" And he said that he GOT it , as in he bought it some time ago. He didn't tell her it was a present because he didn't want her to question him who got him the hoodie. 
Now I know all this because he told me he was going out with friends and that she was gonna be there too and he told me he is gonna wear the hoodie I got him. 

I told him how upset that made me and he said that he just didn't want any trouble with her or get questioned by her. 

I don't know, maybe I am in the wrong, I just got upset cause he said he bought it, he didn't have to say that it's from his new girlfriend, could've just said he got it from a friend or something. I made quite a fuss about it because I searched for it a long time and found it really hard and was so happy when I did cause I knew it would make him happy and he just dismissed it like that, that's what upset me really. 

So reddit, AITA for getting upset? 

TL;DR Got boyfriend a hoodie, ex asked him where he got that from, he said he bought it and I got upset because it was my gift to him. 