Caught my Boyfriend's brother staring at me naked?

So my boyfriend and I were at a cottage last weekend with his family. He had a little too much to drink, so we decided to go to bed early. We were both naked in bed and didn't have sheets on as it was too hot.

At some point in the middle of the night, I woke up to find his brother standing in the doorway just starting at me. I don't know if he could see my face, but I was awake. As soon as I saw him he closed the door and walked away.

I really don't know what to make of this. I don't know if he was just drunk and confused or was being a perv.

I didn't mention anything to my boyfriend yet, because I don't know how he'd react. What should I do?
Updates
+1 y
I forgot to mention, our door was closed. He deliberately opened it.
Updates
+1 y
It complicates things even more that he and his girlfriend were sleeping in the room next to us.
Caught my Boyfriend's brother staring at me naked?
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