when he pressures u
then break up with him
If he is often seen using a skateboard.
you just have to trust him
The only way to know is for him to tell you.
or he dont clean up his mess. or he left right after.
You could try internet stalking using the information you DO know about him. The more you know, the easier it will be.
If you find he is only contacting, seeing you or coming around when he wants or needs something then chances are he is using you.
You will know when he flirts with you, makes a lot of eye contact, and when he is using romantic body language.
Well if your a guy and you are wanting to know then it is having your penis stroked and or rubbed by someone using their feet.
Just to let you know I don't know this girl who is being hit or the guy who is hitting her all I know is they live close ( I won't say how close) and that I am thinking that if I see it I confront him without using violoence in front of her. Cause I want her to know that I am not like that.
http://www.wikihow.com/Know-if-a-Guy-Likes-You