The two were both at a private party for the launch of Angie Banicki's new book 30 Before 30 at the Spare Room inside of the Roosevelt Hotel.
And while the evening outing wasn't exactly a date night, the two were definitely together and hanging out in the same small clique.
A source tells E! News that R.Pattz and Penn left around the same time after mingling with guests by the bar area and the back room.
A second insider says that the Brit was quite the spectacle at the intimate gathering.
"Girls were all flirting with him," explained the eyewitness.
Both left separately, according to the insider, but were with the same group of approximately four people throughout the night.
Of course, it would be far too obvious if the duo packed on the PDA during the party, so we're told that they remained friendly and not touchy-feely whatsoever.
When the Penn rumors first surfaced in late September, insiders told us that it would be premature to label them as anything more than friends. But things could have definitely changed since then. Right?!
This outing comes on the heels of Pattinson being spotted reuniting with his ex-girlfriend Kristen Stewart in Los Feliz just a few days ago.
The two were seen driving in separate cars after secretly meeting up for a few hours.
But don't get too excited Robsten fans, we're told by a source close to the Twilight hunk that the meeting was nothing more than friendly.
A source told E! News that while "there was lots of animosity after the split," the two have "moved on and gradually gotten over it."
The insider added that "they are cordial now" and that pals "honestly believe they will not get back together."