The 23-year-old British singer squirmed when actor Aaron Taylor-Johnson mentioned the 21-year-old American model while confirming he named his chickens after the Kardashian-Jenner family.
"There's Kylie, Kendall, Kourtney, Khloe, Kim, Kris and Caitlyn," Taylor-Johnson told host James Corden as Styles widened his eyes and reached for his drink. "And they're called the Kardash-ickens."
"They lay [eggs] every day," he added, leading Styles to exhale and take another sip of from his mug.
Corden teased Styles by asking, "Do they lay every day, Harry?" but received no response.
Styles and Jenner first dated in 2013, and have reunited several times since. Entertainment Tonight reported this month that Jenner is officially seeing A$AP Rocky after being linked to the rapper for months.
"I don't think you will be seeing them make a public announcement anytime soon, but there is something going on there for sure," a source said. "It's been going on for a while. Kendall is happy."
Styles got similarly flustered when ex-girlfriend Taylor Swift was brought up in an interview with BBC Radio One last week. He said his song "Two Ghosts" is "pretty self-explanatory" when asked if the track is about Swift.