relationship issues. please read and reply!?

[Shyann]

My boyfriend and babydaddy of almost 2 years has only ever been in love with one other girl. they were together for 2 or 3 years but broke up almost 3 years ago. he still has 3 pictures of them together in his profile pictures album on facebook. I asked him to delete them and he said no! hr said he won't delete them because it has been over 4 years ago and because its just the "principle" of it ( whatever the hell that means) he told me that I was just being childish and emotional and insecure. I said that none of that is true and I want him to delete them simply because I don't want MYYY boyfriend to still have pictures of him and his ex girlfriend on there. he says hes not giving into my childish ways and REFUSES to delete those 3 pictures. he said he won't do it because its all in the past and before us. but I feel that if its in the past and none of their relationship matters to him anymore then it should be no problem to just delete thr pictures! even if it was a matter of me just being emotional, insecure, and childish (which its not) I feel like he should STILL just delete thr pics... why is it such a problem to just delete them and let the pics go if he no longer cares about any of that and loves me is the question im asking him? Do you guys feel like im right or wrong in this situation????