This is the reverse of the usual argument, I think!
I used to have really long hair, but recently got it cut to above my shoulders. DP really liked the new cut, said it looked more sophisticated. I liked it too, but think I am going to grow it out a bit (NOT as long as before). When I mentioned it, he was all 'oh no, don't'. When I asked why, he said I would look like a primary school teacher! (wtf?) Now he's saying, 'are you going to get your hair cut soon?' and has also hinted that soon I will be 'too old' for long hair (I'm 27).
I'm thinking, sod you, an am going to grow it anyway, but can feel the waves of disapproval. AIBU?