Niall Horan, Hailee Steinfeld
Rumored lovers Niall Horan and Hailee Steinfeld were spotted dancing, singing along and joking around with each other at a Backstreet Boys concert in Las Vegas on Saturday. Pictured: (L) Horan attends Q102’s Jingle Ball 2017 Presented by Capital One at Wells Fargo Center on Dec. 6, 2017 in Philadelphia. (R) Steinfeld attends Republic Records Celebrates the GRAMMY Awards in Partnership with Cadillac, Ciroc and Barclays Center at Cadillac House on Jan. 26, 2018 in New York City. Michael Loccisano/Getty Images for iHeartMedia; Jamie McCarthy/Getty Images for Republic Records

Niall Horan and Hailee Steinfeld fueled dating rumors when they attended a Backstreet Boys concert together in Las Vegas on Saturday night.

In a series of videos shared by a fan on Twitter, the One Direction member and the “Pitch Perfect 3” actress are seen dancing, singing along and joking around with each other as the boy band performs their hits at Sin City’s Planet Hollywood Resort and Casino.

Horan and Steinfeld reportedly spent more time together after the concert. A source told Entertainment Tonight that the pair headed to XS Nightclub in Wynn Las Vegas, where they sat together at a stage table with a few friends, sipped on Absolut Elyx cocktails, and enjoyed a DJ set by Diplo.

Fans started speculating that Horan and Steinfeld were dating after the 24-year-old Irish singer shared a sweet birthday greeting to the Oscar-nominated actress on Instagram last December.

The dating rumors between them continued after they’re spotted together at London’s West End production of “Hamilton” on Jan. 2, and after the “Slow Hands” crooner attended a birthday bash for Steinfeld’s older brother, Griffin, a week later.

When previously asked about the speculations that she’s dating Horan, Steinfeld didn’t exactly deny the rumors. “I feel so lucky that [my fans] care enough about me to know what I’m doing every second of every day, but I think that sometimes it’s hard for people in general to realize that there are boundaries to a person’s life and personal life” the 21-year-old “True Grit” actress told Us Weekly last month. “I am a very private person. I do love that I have the opportunity to share with them what I’m comfortable with and they’re there to listen and support me.”

Steinfeld was previously linked to Charlie Puth and Justin Bieber. But the “Let Me Go” songtress denied having a relationship with both recording artists. According to Us Weekly, Steinfeld was still with her boyfriend, Cameron Smoller, as of May 2017. But as E! News pointed out, the two are no longer following each other on social media, and Steinfeld has not appeared on Smoller’s Instagram since Nov. 15, 2017.

Do you think Horan and Steinfeld are secretly dating? Or are they just close friends? Sound off in the comments section below!