Gwen Stefani has no doubts Blake Shelton is the one for her. Five months after the Grammy winner, 46, connected with the country star, 39, on the set of The Voice, “she’s head over heels,” an insider says in the new issue of Us Weekly.

And she’s not afraid to show it. The singer — who recently admitted her new single “Make Me Like You” was inspired by her man — cuddled with Shelton during the February 27 wedding of his onetime Voice mentee RaeLynn Woodward, 21. The next night, they flew cross-country back to Stefani’s home turf, making their red carpet debut in L.A. at Vanity Fair’s glitzy post-Oscars party.

Stefani, dressed in an eye-popping sheer Yanina Couture gown, posed for photos hand in hand with Shelton on the red carpet. Inside the party, “they made out,” says an onlooker. They continued the PDA at manager Guy Oseary’s bash. Says a partygoer, “They were dancing together and kissing against a wall. They’re completely infatuated.”

Still, a Stefani source says the relationship is more than mere puppy love. Fully recovered from ex-husband Gavin Rossdale’s alleged infidelity, “she’s in a good place,” a source says of the mom of Kingston, 9, Zuma, 7, and Apollo, 2.

Echoes another insider of Stefani and Shelton, who ended his four-year marriage to Miranda Lambert in July: “It’s definitely serious.”

For more on Stefani and Shelton’s romance, including how she keeps the relationship fun, pick up the new issue of Us Weekly, on stands now!

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