Boyfriend lying about drinking

Ok so my bf tells me everything and knows I don’t like it when he drinks. Today he gave me is phone to find something in his snap memories I was asking about. I found videos of him tipsy taken a few weeks ago and asked him about it. He told me he had started drinking after I said goodnight and didn’t want to tell me the next day because he thought I’d be mad.

I would’ve been a little upset because he’s not legal and took his dads alcohol but I’m way more upset that he tried to hide it from me and had no plan to ever tell me. Is it wrong to be upset? Am I being too overprotective?