Am i using this as payback on my cheating ex ?

ok so a few weeks ago just shortly after my ex broke up with me over facebook for his current girlfriend who is returning to france shortly . myself him his new girlfriend and a mutual friend of his where playing poker( its college theres nothing to do) and the mutual friend left to take a fone call and my exs girl left to use the loo , anyways my ex and i where making small talk and i anounced that i got an internship in new york this summer ( a graphic design internship , which is both of our dream) he said he was happy for me , which i no he wasnt cos hes the type to be self obessed and the type that isnt happy for annoyone . 2 mins later after telling him that his girl walks back in and so dose the mutual friend and my ex starts pokeing his girl in the side playful while starting at me . what do u think this mean ?