To flop ones flaccid penis in, and around another person's stretched anus, using a 'windmill' motion of the penis.
For Heterosexual 'Wingwanging' one example would be:
"Sophie was walking funny due to the severe Wingwanging Ian gave her anus last night"
For Homosexual 'Wingwanging' an example would be:
"Mike and Will loved to Wingwang each other before and after sex"