In the black-and-white shot, Hudson has her arms around Fujikawa's neck as they share a loving kiss.
"Happy 34th birthday baby 🎂," Hudson captioned the pic. "I love you ❤️"
Hudson has been dating Fujikawa since 2016 and they welcomed their daughter, 1-year-old Rani, in 2018. Back in April, Hudson appeared on Watch What Happens Live With Andy Cohen and confirmed that her sex life with Fujikawa has been great while quarantined due to the coronavirus.
"I think it's even more than that. I think it's positive for knowing that I'm with the right person," Hudson said. "There's nobody else I'd want to be quarantined with right now," she added. He's just the best."
In the December issue of Women's Health, Hudson called Fujikawa "the best man."
"It's the first time I feel like I have a real teammate in this," she said. "We're able to pick up where the other one has to leave off. If I have to go to a dinner meeting, he can be home."
"His number one priority is family," she continued. "And when we have our disputes, I feel the thing that allows us to get through them is having the same ultimate goal, and that includes being in each other's life. It just feels so nice."
Despite her love for her beau, Hudson told ET last September that she's not thinking of walking down the aisle anytime soon.
"Oh god! I'm not thinking about that," she said at the time. "Yeah, especially after one wedding, you're like, 'Whew!' It's a lot of work but yeah, not anytime soon but I love the man!"