AITAH for not wanting to get my hair cut?

So my parents are very prim and proper and conservative, I feel like it took a lot to convince them to let me grow my hair out over hockey and lacrosse season, but I said after it was done I needed to get it cut short. I said sure, and by now it's grown out to a nice mullet/flow style. However, lacrosse season is over and they are wanting me to cut it short.

I asked why, and they said I made a deal and short hair is better for the summer. I've also got a formal wedding coming up, and they say it needs to be off the collar for that.

AITAH for not wanting to get it cut?