Which preposition to use with chummy

with Occurrences 8%

"I was rather chummy with him when we were in the Fifth, and he was all right then, but now he seems to be running to seed as fast as he can; and I believe it's a great deal that fellow Fletcher.

over Occurrences 1%

But still, there were all sorts of last things to be thought of, and Lionel Varick and Bubbles became quite chummy over the affair.

Which preposition to use with  chummy