The pop star took to her Instagram stories on Thursday to celebrate fiance Matthew Rutler's special day, sharing a gorgeous throwback photo from her 2014 pregnancy with daughter, Summer Rain.
The black-and-white image, adorned with pink hearts and arrows pointing to her baby bump, features Aguilera lying on her back in a sheer white v-neck dress while a shirtless Rutler leans in for a kiss. It was the same photo from her shoot with Vmagazine, one that also featured the 37-year-old singer naked with her bump on full display.
The former Voice coach also shared a touching shot of her and Rutler in a sweet embrace while he kisses her forehead.
"Birthday boy...," Aguilera wrote. "To a wonderful father, loving man and hardest worker I know."