A discreet way to refer to a nipple erection (see also nipple freeze, nipple stand, nippleboners, nipplection, nippleitis, and nipplitis). Derives from Tom Cruise's tendency to "act" with his fingers: pointing with both forefingers to emphasize something he's saying. Particularly evident in Jerry Maguire (the finger acting,that is, not the stiff nipples). The term is not gender-specific.
by Longsilver May 20, 2006