Jennifer Lopez and Ben Affleck put on a united front for their children, reuniting for the first time in 7 weeks. The couple reunited for Fin Affleck’s school production on Thursday but arrived separately and didn’t appear happy to see each other as rumors swirl that the actor is done with their marriage, RadarOnline.com has learned. It’s been 47 days since they’ve been seen in public together, and an eyewitness recounted the icy affair as the two met in a parking lot on Thursday before the show. “Ben did not look happy to see J Lo as she arrived at a show for one of his kids,” the insider tol…