AIO for being upset by boyfriend complimented another girl in front of me?

My boyfriend (29M) and I (22F) went to the mall earlier today and went around to a few stores. When we were paying, he stared at the cashier for like 15 seconds before apologizing and saying she had really pretty eyes. She looked completely confused, I asked him if she knew her and he said no. He didn't elaborate further, but I aslo didn't ask any more questions.

I was upset, but felt like I had no reason to be. We have a child and he's never cheated on me or did anything shady. I just felt insecure and kinda jealous like he rarely says stuff like that to me. For some context, he's on the spectrum and has always had issues with expressing how he feels and social interactions, but it didn't seem like he struggled with that one lol

(using a throwaway bc he also uses reddit and knows my main account)