Jennifer Lopez and Ben Affleck are going from zero to sixty, with the singer seen spending time with Ben's son Sam in the Brentwood neighborhood.Ben and Jen reunited in May, 17 years after they ended their engagement, and the two have been pictured with each other's families since.But Jen and her 13-year-old daughter Emme hit Brentwood Country Mart with Ben and Sam on Friday, with onlookers spotting the four enjoying dinner and shopping.MORE: Alex Rodriguez makes dig at Ben Affleck when asked