The source told Us Weekly that Gaga has been bonding with Renner and his daughter, Ava Berlin Renner, 6.
The insider told the outlet, "Chris didn’t treat Gaga very well toward the end of their [two-year] relationship," adding, "she really leaned on Jeremy in the weeks after it ended."
As we previously reported, one week ago, a source exclusively told the publication that Gaga, 32, and Renner, 48, have been "hanging out."
An insider didn't "believe it’s romantic at this point," however, it that the singer has "been spending a lot of time" with the father-daughter duo.
Renner shares Ava with his ex-wife Sonni Pacheco (2014-2015).
The relationship rumors between Gaga and Renner came one month after the songstress ended her engagement to talent agent Christian Carino, 50, after dating for two years.
The former couple, whose romance was confirmed in February 2017, had become engaged in November 2017.
Since her split with Carino, Gaga was spotted hanging out with Ken Todd and Lisa Vanderpump at their Pump Restaurant.
For more updates, stay tuned to Frostsnow.