Pratt, 39, uploaded to Instagram on Thursday a collage of photos of himself with Schwarzenegger in celebration of her 29th birthday.
The photos feature Pratt kissing Schwarzenegger on the cheek and the pair posing together while wearing animal-print face masks. This marks the first time Pratt has publicly posted about his affection for Schwarzenegger.
"Happy Birthday Chief! Your smile lights up the room. I've cherished our time together. Thrilled God put you in my life. Thankful for the laughs, kisses, talks, hikes, love and care," the actor said.
Schwarzenegger commented on the Instagram post writing, "I love you."
Pratt was previously married to actress Anna Faris for eight years before they called it quits in August 2017. Pratt and Faris agreed to live near each other as part of their divorce settlement as they co-parent their 6-year-old son Jack.