Can u be friends with a ex heart throb?

we were friends in college , never in a actual relationship , but v liked eachother though . now we are in the same proffesion due to which v get to meet eachother some times. he has a girlfriend now, but v still feel some connection between us . i dnt want to mess up my life or his . v have a silent comitment of sending an sms every week ( as if to say am thinking of u ) yes even he msgs me though these sms are sometimes just regular jokes , or friendship msgs, i sense trouble ahead . do u think i should just drop this whole friendship thing .am confused. yes he still seem to like me . somebody talk me out of this , put some sense into me.