Photo: Axelle/Bauer-Griffin/FilmMagic; Rachel Luna/FilmMagic

Evan Peters, Halsey, Emma Roberts

While attending an event on Saturday night celebratingAmerican Horror Story‘s 100th episode, Peters, 32, and Halsey, 25, made theirred carpet debutas a couple, one month after they werefirst seenon a date. The pair, decked out in matching polka-dotted Sonny and Cher Halloween costumes, were seated one table away from Roberts and didn’t shy away from making out during the party.

Emma Roberts.Axelle/Bauer-Griffin/FilmMagic

Emma Roberts

Roberts is currently starring inAHS‘s ninth season, which is the first installment of the show to not include Peters in its cast. In aJune cover story forCosmopolitan, the actress shared her difficulties with separating from Peters after their longterm on-offrelationship,saying: “I think that no matter who you are or what you do or wherever in the world you are, anything ending is hard. Losing something is hard.”

Over the summer, Roberts went ondateswithGarrett Hedlund, 35, but a source told PEOPLE the actors are taking it slow.

“Emma is newly single and neither she nor Garrett are in the right headspace to be in a serious relationship,” thesource saidat the time. “They’re just having fun hanging out and hooking up.”

Variety/Shutterstock

Halsey, Evan Peters and Sarah Paulson

Halsey and Peters were first romantically linked after beingspotted togetherat L.A.’s Six Flags Magic Mountain on Sept. 21. One onlooker said Peters appeared to be “flirting” with Halsey as they waited in line to board a roller coaster at the amusement park.

Per multiple outlets, Halsey, who also had a previous relationship with rapperG-Eazy, voiced a crush on Peters as far back as 2012 via Twitter, reportedly tweeting, “Seriously Evan Peters stop making me attracted to alleged sociopaths and accused murderers….,” referencing the actor’s creepyAHSroles.

American Horror Story: 1984airs Wednesdays at 10 p.m. ET on FX.

source: people.com