Should I cut my son's hair?

Hi, I have a 15 month old son who has super curly blonde hair! It's soo cute, but I'm afraid if I cut it it won't grow back curly, that's what happened when his dad was a baby. Should I cut it or let it grow a little longer. I don't want him to have long hair by any means, but his curls are too cute. Anybody been there??