I think my son hurt this girls feelings real bad

My son just started 8th grade and there's this girl that I think likes him. He is very oblivious to these things. He has autism so he typically doesn't notice these things. I dropped him off and she came up to the car to greet him and I waved hi and he was just staring at her fafe and says "What's all over your face?" This poor girl looked devastated and said "Makeup." He stares at her again for a little bit and says "Oh." And walks away! That poor girl! Now her makeup was not looking great. She's probably just learning how to blend properly and that's fine. My son is so blunt to and I don't think he's used to heavy makeup which is why it confused him. We are gonna have to have a second talk about not saying everything that comes to mind.