I find women with short hair masculine and I can’t find them attractive it’s a big turn off for me, am I not allowed to reject someone I don’t find attractive? Wdym it can change in a few months? Why don’t you go and marry a fat woman she can lose weight in a few months too.
You can ask them to grow it out. It takes minimal effort on their part.
Secondly, comparing weight and hair length is disingenuous.
One requires minimal effort and the other requires discipline, mental fortitude and good/average genetics.
Regardless, it’s not the end of the world if your partner isn’t skinny.