Alec and Hilaria Baldwin prep for baby girl

Parents-to-be Alec Baldwin and Hilaria Baldwin spent Father’s Day Eve at the Dive into Summer event at Sagaponack’s Wolffer Estate Vineyard to benefit Group for the East End.

While waiting for their baby girl to arrive at the end of the summer, the Baldwins will spend their time out east raising money for causes near to their hearts — and prepping for baby.

“We will be ready when she comes,” Hilaria told us.

For this newest addition to the family (Hilaria wouldn’t reveal a name yet, saying “You’ll have to wait to find out”) , it’s Hilaria who will be enforcing the rules.

“She’s very tough!” Alec said of his wife.