Beyonce and Jay-Z's twins are barely 4 months old but they're already moving like royalty. 

The Carters arrived at a New York heliport Wednesday with their entire brood in tow ... big sis Blue Ivy was there, along with Rumi and Sir. It's the first time the whole fam's been seen together since the twins arrived in June.

Hov was a hands-on dad carrying one of the twins, and got a helping hand with the other.

The superstar couple just dropped a fortune on a Hamptons home, about 35 minutes away by chopper. The Carters don't do traffic.