Patriot Rob Gronkowski helped celebrate the second anniversary of the Boston-based Paint Nite on Sunday. Gronkowski’s own painting, made during the event at Ned Devine’s, was auctioned off to benefit the National Brain Tumor Society. If you’ve never been to a Paint Nite, it’s basically a social event where people get together, drink, and learn to make a work of art. The activity, which is now run in 77 cities, was founded by Daniel Hermann and Sean McGrail. Paint Nite appears to be running a bunch of local events this week, including Tuesday-night art activities at Stadium in South Boston and at Perfect Game Sports Grill and Lounge in Worcester.