The Grammy-winner is known for having no filter.
Sharing the latter on Instagram after recent pictures of the couple squabbling, Carey gushed about his wife, whose epic tour has been a huge success.
"Congrats baby! All I can say is "wow," I'm so proud of the person you are, you've pulled off the impossible,’ he wrote.
"Record-setting tour, chart-topping album, amazing mother, and loving wife."
While Pink was thrilled by the gesture, she appeared to deem it out of character and unexpected, based on her comments.
"Thank you babe.... I told the audience about this last night and we all decided that Hell has officially frozen over," she joked on Instagram.
The couple, who have a daughter Willow, aged eight, and a son Jameson, aged two, have admitted to enduring marital issues in the past.
However, it appears the love is stronger than ever, with her husband writing:
"I'm so fortunate to be shotgun with you through the whole experience. I love you so much, and can't wait to celebrate life with you after the tour."