On Sunday, the 21-year-old Stranger Things star posted a sweet tribute to her hubby to honor their first wedding anniversary.

"1 year married," she wrote under a snap from their Italian nuptials. "I love being your wife."

Jake returned the favor in an Instagram post of his own, writing, "One year in the books, many more to go."

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"I love you so much my beautiful wife," he continued. "Happy anniversary."

The milestone comes on the heels of the couple's bombshell announcement that they quietly adopted a baby girl over the summer.

Millie and Jake have not shared further details about the addition to their family, but the baby's doting grandpa, Jon Bon Jovi, broke his silence on her arrival during a new interview.

"It's crazy, but great. Wonderful," he gushed in a chat with influencer Bunnie Xo, per a TikTok clip shared on Sunday.

"They adopted a girl, we met the baby, obviously, and immediately that becomes your grandchild, you know what I mean? Your baby."

The 63-year-old rocker admitted he can't get enough of his first grandchild, adding, "I want to see pictures, like, every other day. I'm that pain in the butt guy already."

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Jon also praised his daughter-in-law as a "sweetheart" and explained that he admires her strong work ethic.

He shared further that he and his wife, Dorothea, gave Millie and Jake their blessing to get married at a young age because they are "mature beyond their years."

"She comes from a family where her parents are still together and they married very young," the musician said. "Her and Jake fell in love, and we just thought, 'Okay, we will support this.' And it's working out."