Must you love your immediate family unconditionally if you know they drive you crazy? And must you show up for family gatherings like Christmas if it always evolves into a vicious fighting match? Is love nothing more than propinquity, that is biological closeness? Leslye Headland's "Cult of Love" produced by Second Stage at Broadway's Helen Hayes Theater, a searing comedy-drama, reminds us that most American plays ot…
