I'm with GF's Dad on this one. You're just a boyfriend, not even a fiance. You're not part of the family...yet. Non family members don't get to be in family photos. Event photos, yes, but not family ones.
He also goes back and very badly crops others peoples heads onto her steps sisters exes. It was awkward as hell when her niece was old enough to notice her dad being cropped over last year.
Taking pics without letting SOs is is understandable. Refusing to get to know someone because you might be gone is not. It goes much deeper but it’s too much to type.
Sorry about that.