Gisele Pens Love Letter For Tom Brady's 44th Birthday, 'Too Good To Be True'

Gisele Bündchen is channeling her inner Frankie Valli for Tom Brady's 44th birthday ... penning a mushy love letter to her man -- saying, "You’re just too good to be true."

The international supermodel took to her Instagram on Tuesday to deliver the G.O.A.T. his special birthday greeting ... posting a cute pic of the couple and quoting a Frankie Valli & The Four Seasons classic hit.

"You’re just too good to be true," Gisele wrote. “Can’t take my eyes off of you. You’d be like heaven to touch. I wanna hold you so much. At long last, love has arrived. And I thank God I’m alive. You’re just too good to be true. Can’t take my eyes off of you."

Gisele finished the post with a message in both English and her native language of Portuguese ... adding, "Happy Birthday love of my life! Thank you for sharing your life with me! I love you."

Brady was clearly thrilled with the birthday post. In fact, he even replied by commenting on the pictures in Portuguese! "Te Amo Tanto meu Amo Da minha Vida." Translated to English, he said, "I love you so much, love of my life!"

Of course, Brady's been working on his Portuguese since their relationship began ... and all the lessons are clearly paying off!!