Flirting

Guys, Why does he start to grab/squeeze my side or waist now?

I have a friend who likes to squeeze my side or waist now and I don't know why. If he's being flirty or what.. I don't know if this is relevant but we sent each other pictures and he started doing that the 2nd time i seen him in person after sending pictures. But when he walks past me he'll just give me a little squeeze. I doubt he likes me though.
Guys, Why does he start to grab/squeeze my side or waist now?
Post Opinion