If he ALREADY has leaked these photos to others, he has then crossed very serious "revenge porn" and/or child porn distribution laws. His cellular phone carrier WILL FULLY cooperate with local AND FEDERAL (IF these pictures were sent to phones CROSSING state lines ) law enforcement.
If however, he has NOT yet leaked these photos, it serves as friendly advice he:
Delete ALL such photos because
A) you were UNDERAGE when you took them and B) given that it IS effortlessly easy for LAW ENFORCEMENT to ACCURATELY TRACK DOWN EVERY cell number he sent such file(s) to, his complicit guilt would be easily proven---both in possession of AND distribution of child porn, which both are major prison offense felonies.
B) There is NO such thing as complete file deletion--be it on a PC or cellular phone; it's wise he DESTROY said cellphone ,when comes time to replace it.