Do guys notice touch?

Anonymous
Today in one of my classes we were going over our latest test and, as I was looking through mine, I came across a problem I didn't understand how to solve. In that class we work in groups often and it is encouraged that we consult our group members before consulting the professor. However my group (which includes my crush who sits next to me) didn't know how to solve it either. So I turned around in my seat and asked someone else. As they explained the solution to me, my original group members crowded around my table. Soon enough my crush turned around as well; but once he did he leaned in so that his upper arm rested against mine. For nearly five minutes we stayed like this, neither of us moving.

There have been moments when I would touch him and he never moves away. Often I catch him looking at me. Sometimes I'll be working on a paper and notice him staring at me out of my peripheral vision. We joke around with each other all the time and he mimics my gestures/voice from time to time. Plus, whenever he is next to me his entire body faces my direction; everything from his shoulders to his legs will be directed towards me. I read somewhere that this is a common sign of interest, but there are numerous misconceptions on the internet. The only issue is that I don't know how to tell the difference between a guy being flirtatious and a guy being friendly.

So do guys notice if they are touching a girl (or vice versa)? If so, what would cause a guy to remain in the position?

Also guys, could you outline the difference between flirty and friendly behavior on your end?

Thank you!
Do guys notice touch?
5 Opinion