Tom Papa frequently opens for Jerry Seinfeld on his nationwide theater tour dates, and Seinfeld is returning the favor this Thursday night by performing at a fund-raiser show Papa is throwing at Gotham Comedy Club for his sister’s charity, City Green.

Papa explains via MySpace bulletin today: "A little background on the show… I’ve got a sister and she runs a charity called "City Green" that builds gardens in wasted urban spaces. Brings the community together, makes people happy, real do-gooder stuff! But I’m a do-gooder too and I’m putting on a fund raising show for her at the Gotham Comedy Club next Thursday, April 24th at 8pm. All proceeds go to her charity."

What more do you need to know? Right. The lineup, in addition to Seinfeld and Papa, includes Jeff Garlin, Colin Quinn, Kevin Brennan and Keith Robinson. It’s a $40 cover and two-drink minimum. Get your tickets before they’re gone.