Guy's Behavior

What does it mean when a guy wipes something off your face?

I went to lunch with a guy today. We're friends, but not very close. We used to work together. This is our second lunch. We were eating greasy tacos and I guess some of the grease got on my face, so he reached over and wiped it off. No warning or anything. Whenever this has happened with other people, they just say, "Hey, you've got something on your face." But he just went for it. I didn't realize we were that comfortable with each other. I just thanked him and we kept talking. Does this mean anything or is just a sort of brotherly thing to do? (And, yes, I'm in my 30s and should know the answer to this, but men still baffle me.)
Updates
1 y
Just to update everyone, he was totally into me and turns out he wiped my face because he wanted to touch me. We've since gotten much closer and I asked him about it. So... most of you were incorrect. lol
What does it mean when a guy wipes something off your face?
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