Jon Gosselin isn't the only one having fun. Kate Gosselin spent Thursday evening with three much-younger men: the Jonas Brothers.

See photos of Jon and Kate's happier days

The mother of eight took two of her daughters, 8-year-old twins Cara and Mady, to see Kevin, Joe and Nick Jonas at their concert at the Wachovia Center on Thursday in Philadelphia.

See more photos of Jon and ex-girlfriend Deanna Hummel

The trio and one of the twins' friends arrived at the show, which started shortly after 7 p.m., in a black stretch limo. No film crews were with them at the concert. Shooting for Jon & Kate Plus 8 -- which returns to TLC on August 3 -- went on earlier in the day at the Gosselin's $1.1 million Wernersville, Pennsylvania, home.

Look back at the wild past of Jon's other girlfriend, Hailey Glassman

Meanwhile, Jon has been busy with a new girlfriend in NYC. He made headlines on Wednesday after having dinner in the Hamptons with Star tabloid reporter Kate Major -- as well as Michael Lohan and Real Housewives of New York City star Jill Zarin.

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