Bradley Cooper's Back on Hollywood Scene as a Single Man

Bradley Cooper's clearly not sweating his reported breakup with Irina Shayk ... he's back on the Hollywood scene and looking quite comfortable too.

The "A Star is Born" star/director hit up the Sunset Tower lounge Monday night with some of his buddies. Bradley showed up at around 8:30 PM and was seen leaving about 2 hours later.

Hardly a night out raging on the town -- but after 4 years of practically married life, and co-parenting a 2-year-old ... he might need to ease in to single life.

Meanwhile, Irina's hardly showing any outward signs of heartbreak amid the reports she and Bradley are dunzo -- she's just hard at work. The model's been posing all over Iceland for a photo shoot.

She posted this pic from her day at the office, and fans teed off on her baby daddy in the comments, saying things like, "Bradley is crying somewhere" ... and, "Biggest L of 2019 goes to Bradley Cooper."