Eva Mendes Meets Ryan Gosling's Mom

By Pernilla Cedenheim and Alison Schwartz

01/03/2012 at 12:05 PM EST

Ryan Gosling welcomed in the New Year with his two leading ladies: girlfriend Eva Mendes – and his mother, Donna.

After spending some quality time together earlier in the day Sunday, the mother-son duo met up with Mendes to go to an AMC movie theater in uptown Manhattan.

"They all hung out and went to the movies together," a source tells PEOPLE. "Ryan and Eva seemed very happy."

PHOTOS: Ryan Gosling: Mr. Hot Shots of 2011

Gosling, 31, and Mendes, 37, who first stepped out together in September, jetted from Los Angeles to New York City on Friday, once again looking very much like a couple.

"They kept kissing and hugging while they waited to board their flight," an onlooker at the Los Angeles International Airport tells PEOPLE. "Eva looked gorgeous and kept smiling."

And it looks like they had their midnight kiss (and then some!): The couple were spotted getting cozy when they left Manhattan's Bowery Hotel for a party on New Year's Eve.

"While they waited for a cab outside the hotel, they kept kissing," an onlooker tells PEOPLE. "They both looked very happy."