it is the love of your long hair, accept his words, his fantasy of cutting it, do not allow it.
But it will never be the same, the love without longhair.
Sometimes i like to cut it too but the next day i am happy with my wife (i will always if she had no hair too, do not misunderstand ) wearing her hair as a crown, in an updo or loose and everything between it.
It is you, with your pride of your longhair, he has te accept that.