Channing Tatum and Younger Model GF Inka Williams Go Instagram Official

Channing Tatum's gone IG-official with his new model girlfriend, Inka Williams ... and it was for the perfect moment -- his birthday!

The 25-year-old went all out on her IG Story, celebrating Channing’s 45th over the weekend with a collage of PDA-filled pics. She captioned it, “Happy life to the handsomest, kindest, funniest, stoopidest, most gorgeous human ever!!!"

Aussie babe Inka wrapped up the caption with, "Merci for making life beautiful and fun," and threw in a little French flair with "JTM trop fort," which means "I love you a lot."

Despite the 20-year age gap, it’s pretty clear Channing and Inka are very into each other, already sharing a bunch of great memories -- and that’s after news broke last month that they started dating.

Channing’s dating history is stacked -- he was married to Jenna Dewan for 10 years, dated Jessie J, and most recently had a thing with Zoë Kravitz.