The 38-year-old actress said in a post on Instagram Stories that Novak sent her "the prettiest" bouquet on her first day of filming the movie Late Night.
Novak gave Kaling white roses and a note reading "Congrats on Day 1 'Love' 'B.'" Kaling joked about the "classy" gift in the caption.
"The prettiest flowers from @picturesoftext," she wrote. "White flowers are very classy for me. I'm sorry; white fleurs."
Kaling and Novak co-starred as Kelly Kapoor and Ryan Howard on the NBC series The Office. The pair dated on and off throughout the show's run, and have maintained a "weird as hell" relationship since.
"He is not my boyfriend, but he is not my best friend," Kaling said in the June 2015 issue of InStyle.
"I guess you could describe our relationship as 'romantically charged camaraderie with loud arguments,' but I don't think Facebook would accept this as a new status," she joked.
Kaling welcomed her first child, daughter Katherine, in December. In addition to Late Night, she plays Priya Patel and serves as an executive producer on the new NBC series Champions.