In a surprise turn of events, Demi Lovato and Jesse McCartney joined Jonas Brothers on their Jonas20: Greetings From Your Hometown concert at MetLife Stadium, New Jersey, on August 10. To commemorate their 20th anniversary and to promote their seventh studio album by the same name, released on August 8, the pop trio, Kevin, Joe, and Nick, kicked off the tour on Sunday.The Jonas20: Greetings From Your Hometown tour will have the brothers perform 52 concerts across various US locations, including Michigan, Pennsylvania, New York, and others. The tour is scheduled to end in Montville, Connecticut, on November 14.The tour commenced with a banger show as Demi Lovato graced the stage during Act 2. Demi, who starred alongside the Jonas Brothers in the Camp Rock films, performed This Is Me and Wouldn't Change a Thing with Joe.The crowd erupted in loud cheers and sang along with the artists as many relived their childhood nostalgia. Some fans online began anticipating that Demi Lovato and the brothers might reunite for a possible Camp Rock 3 film.The Jonas Brothers also brought in singer and Summerland alum Jesse McCartney during Act 1 to perform his 2004 hit Beautiful Soul. As clips from the concert began circulating online, netizens also joined in to share their emotions."Demi Lovato and Joe Jonas performing Wouldn’t Change a Thing in the year 2025 is everything to me 😭 Camp Rock 3 is going to be a banger", wrote an X user.JT🪝 @JTsLeagueLINKDemi Lovato and Joe Jonas performing Wouldn’t Change a Thing in the year 2025 is everything to me 😭Camp Rock 3 is going to be a bangerHysteria.EVE 🍭💥 | Specialite EN @Hysteria_EVEEXELINKi'm literally crying so much right now this is my childhoodW @live4gaLINKOmg our childhood icons are back togetherLove Scribbles @LoveScribblesLINKDemi and Joe bringing back the magic, some things only get better with time, just like fine wine and epic comebacks.Several fans were even more surprised to see Jesse McCartney on stage.JAY @coleJJ3LINKtwo 2000s icons on one stage is pure nostalgia overloadVictoria Giddings✨ @victorigiddingsLINKI know this made Jesse’s heart swell. I wish he could sell shows this big because clearly the love is still there.kt @y2kathieLINKWTF JESSE MCCARTNEY AND NICK JONAS MY FIRST TWO CHILDHOOD CRUSHES???? 😭😭😭Jonas Brothers kick off their Jonas20: Greetings From Your Hometown tourThe pop trio is set to venture out on their Jonas20: Greetings From Your Hometown tour for the next 4 months. During their Sunday concert, Jonas Brothers performed three sets, containing songs from their group albums as well as the siblings' solo projects.The opening act comprised songs including Lovebug, Love Me to Heaven, Only Human, S.O.S., Sucker, Meant to Live, Hold On, Little Bird, Summer Baby, Still In Love With You, I Can't Lose, Waffle House, Beautiful Soul, Vacation Eyes, Celebrate!, No Time to Talk, Cake by the Ocean, and Slow Motion.Jesse McCartney joins Jonas Brothers on stage at MetLife Stadium on Sunday. (Image via Kevin Mazur/Getty Images)In their second act, the siblings performed Leave Before You Love Me, Jealous, What a Man Gotta Do, Walls, Love You Better, Chains, What This Could Be, Conspiracy Theory / Just in Love / Bacon / Toothbrush / Delicious / Unsweet / Levels / Body Moves Riff / Dancing Feet, Gotta Find You, This Is Me, Wouldn't Change A Thing, Year 3000, and Burnin' Up.Jonas Brothers ended the show with the encore tracks, Please Be Mine, and When You Look Me In the Eyes.Apart from Demi Lovato and Jesse McCartney, Marshmello, Joe Jonas' band DNCE, Switchfoot, and Big Rob also joined Jonas Brothers as guest artists on the show. After blessing fans with a successful gig at MetLife on Sunday, the brothers are headed to Jiffy Lube Live in Bristow, Virginia, next.