From an ESPN article by R. Shelburne:
McCaffery, Clark's boyfriend, was a player development intern on the Pacers' staff, and he had played against Haliburton in college -- Haliburton at Iowa State, McCaffery at Iowa -- but their friendship grew once McCaffery joined the Pacers.
"Me and Connor would talk all the time about [Clark's] journey," Haliburton said. "But I refused to cheer for Caitlin until she got out of college because I'm not cheering for Iowa."
As the season went on and it was clear the Fever would have a good chance at landing Clark with the No. 1 pick, Haliburton finally relented.