Blow hot and cold

For a week, she couldn't get enough of me. The next week, her interest blew hot and cold, and a week later she dumped me.

He blows hot and cold. He will speak for or against.

Geminis, like air, blow hot and cold. They go this way today and another way tomorrow.

The Xinhua commentary said that Chen "blows hot and cold, behaves capriciously and is a hard man to trust."