It's so awesome for you when your brother's dating a hot model and that hot model has hot model friends your brother can set you up with. Such is the case of Nick Jonas, whose JoBro Joe is dating Gigi Hadid. Try to keep up here ... Gigi's BFFs with fellow it-girl model Kendall Jenner so she set up Joe's bro Nick with Kendall and sparks flew! Got it?

A double-dose of hotness when they double-date, Kendall and Nick complete the Jo Bros/it-girl package with their recent hookup. And all is well in Jonas land -- Nick's just release a new single, "Under You," which is destined to be a hit, and now he's got a hot girl on his arm. He and Joe partied at Craig's last night in West Hollywood, after Nick made a surprise appearance at the iHeartMedia Music Summit in Burbank earlier in the day, to debut the new single.

Apparently pals like Cara Delevigne have nicknamed Gigi and Joe, G.I. Joe, and they're all super happy about this new match ... probably brainstorming nicknames now. They're all going to hang out anyway, so it seemed like a natural fit, a source tells Us Weekly.

The two met over text, according to the report, and hit it off immediately. Nick recently broke up with his girlfriend of two years, Olivia Culpo.

Still, they may not be ready to take their relationship public just yet (too late!): "When they're ready and it turns official, we'll start seeing photos," the source tells Us. And X17 will be there!