This reminds me of the plot of a late-90s RDJ vehicle, Two Girls And a Guy. As I recall, it was one of the first things RDJ made after going through rehab and before becoming identified with Tony Stark/Iron Man. Two women, played by Heather Graham and Natasha Gregson Wagner, encounter each other outside RDJ's apartment building in lower Manhattan. Through conversation, they discover that they are both waiting for, and dating, RDJ. Wacky hijinks ensue.

Disclaimer: I haven't watched it since it hit home video in the late '90s so it may not have aged well.