Selena Gomez and Justin Bieber arrive at the American Music Awards on November 20, 2011 in Los Angeles, California. Credit: Kevork Djansezian/AMA2011/Getty

Justin Bieber and Selena Gomez aren't done playing games with each other.

After Bieber's sold-out concert at Madison Square Garden in NYC on Wednesday Nov. 28, the 18-year-old singer and his on-again love, 20, had a late-night play date at the Times Square location Dave and Buster's, the nationwide arcade/restaurant chain.

The twosome arrived around midnight "arm in arm," a source tells Us Weekly, ready to "play a bunch of games." That included car-racing game Daytona and Super Shot -- plus, befitting their epically up-and-down relationship, the world-famous pair rode the venue's indoor roller coaster.

"They were arm in arm the whole time, and even stole a kiss here and there," the source notes. "They definitely seemed happy and in love and had a great time."

Earlier in the evening, Gomez was just one of thousands of adoring fan watching as the "As Long As You Love Me" crooner performed at MSG. According to a witness, Gomez watched "transfixed" from the side of the stage.

Despite all the ups and downs, Bieber remains smitten as well, another pal explains in the new Us Weekly. "He was desperate to get back together with her," the friend says. "Selena has been worried, but she still loves him."