What does it mean when a guy puts both his hands around your waist?

yeah so today I was with my class in the hallway waiting for class, then this guy in my class put both his hands around my waist, unconsciously I didn't know that he came closer to me, he was standing a few metres away from me, and when I realized he was having his hands around me and then he was standing right next to me, not even a meter away! it was like millimeters between us!