"Miley was doing some post-show flirting with French Montana before leaving MSG and heading to the after-party," an insider says.
"They were getting super close and flirting while drinking out of the same cup," the source added.
Meanwhile, Cyrus and ex-beau Liam Hemsworth have been exchanging texts and the pair even met up in secret in Los Angeles.
The former couple, who called off their engagement earlier this year, are talking again, and regularly getting together.