Bay seniors who suspect the Mission District of harboring the latest expression of hipness, can judge for themselves this Sunday. Head to Dolores Park the epicenter of the new SF Hipsterati. At 3pm memories of Jane Fonda in Spandex will flood back at “Critical Ass” a cheeky performance piece including workout sessions. Free. Or come earlier with your grandchildren and their own pre-filled squirt guns and water balloons. Yes, it’s war, the totally wet kind. From 2-3pm. Free.