Rihanna sure knows how to party.
Rihanna certainly isn't shy about her new relationship with rapper Travis Scott.
The 27-year-old superstar showed some pretty heavy PDA with the 23-year-old rapper/producer on Thursday night at her star-studded New York Fashion Week Block Party, where an eyewitness tells ET they "were all over each other."
At one point, Scott was photographed with his arms around Rihanna and kissing her neck, while she chatted with Justin Timberlake.
WATCH: Rihanna Hooking Up With Travis Scott
"Travis and Rihanna were together all night," another source inside the party tells ET. "After he was done performing, he joined her inside where they spent a lot of time dancing closely and kissing. Travis had his arms around Rihanna's waist when she said hello to Justin Timberlake. They were very touchy feely. You could tell that she's really into him.”
Scott performed at the event, actually taking Rihanna's place when she told production that she "didn't feel like singing in the rain," our source says. But she definitely showed her support for her new man, "cheering like crazy" during his 45-minute set, according to an eyewitness.
Prior to last night's PDA fest, Rihanna attended each one of Scott's three sold-out shows at the Gramercy Theatre in New York, and also enjoyed dinner dates with him.
"They are not exclusive, but could become that," a source previously told ET about the pair, adding that their relationship has been going on for less than a month. "They both are enjoying time together."
Though one thing's for sure -- the "Bi**h Better Have My Money" singer obviously knows how to throw a good party. The Rihanna Block Party, produced by The Bait Shoppe, actually shut down 24th Street between Madison and Park Avenues, and had A-list attendees galore. Before Scott's performance, Rihanna hosted a private dinner for 50 people in chef Jason Atherton's Clocktower restaurant, which lasted about an hour and a half. Guests included Kim Kardashian and Kanye West, Timberlake, Pharrell, Wiz Khalifa, Zayn Malik, The Weeknd, Chris Rock, Timbaland, Gigi Hadid, and Joe Jonas.
After the performance, other attendees at her private party were Nicole Richie, CeeLo Green, Brooklyn Beckham, and Gabrielle Union, though apparently, the crowd was too much for the former Bring It On star. Our source says she and her gal-pal walked right out after taking in the mayhem.
And the party didn't stop for RiRi until well into Friday morning. Our source reveals that after her private party, she had yet another after-party at the Edition hotel until 5:30 a.m., though only 50 people were allowed. She was even spotted asking hotel staff at 2 a.m. if she could get some chicken wings delivered to her at the party.
WATCH: Rihanna Would Totally Back Kanye West for President -- 'Who Wouldn't Vote for Kanye?'
Watch the video below for more on Rihanna's budding relationship with Scott.