Selena Gomez & Fiancé Benny Blanco Ring in Hanukkah Together in NYC

Selena Gomez has been totally smitten and glued to her new fiancé, Benny Blanco ... and she’s closing out the year by his side, going all in for the holidays.

The lovebirds were spotted at author Jake Cohen's Hanukkah celebration in New York on Wednesday, with the host sharing a bunch of photos of them fully embracing the festive vibe.

ICYDK, Benny’s Jewish, and while Selena’s been open about her Christian faith, she was all in for the occasion ... happily by her boo’s side as they celebrated with what looked like a whole lot of fun and frolics.

Jake captioned the images, "Some lonely Jews on Christmas getting lit," as they partied with a big group of friends, including Debra Messing, proving they’ve truly found their NYC holiday squad. And of course, this year, Christmas Day and the first night of Hannukah both fell on December 25.

Things were a bit more intimate earlier this month for the besotted couple when Benny proposed to Selena with a dazzling 8-carat diamond rock -- because nothing says "I love you" like a rock that big!