people that seem to be a little slow in the head can be described as 'doughnuts' or 'doughnut heads' as the jam in the uppermost part of the body of a vertebrate is a metaphor for brain and the subject's skull and the dough is metaphorically speaking the head itself. Usual response to the comment includes 'what are you on about', 'ou, why did you just hit me' and 'stop it, I'm calling the police'.
when someone does something stupid - you sayoi you doughnut
A synecdoche or “pars pro toto” derogatory term for a woman which characterizes her by her vagina. Doughnut=Vagina=Woman. Adding a possesive pronoun indicates a relationship beyond friendship but not necessarily intimate.