To 'Crawl the Wall' means that when one is near the point of ejaculation, the feet are used to propel ones legs and body swiftly up the nearest wall, manoevering ones body upside down thus allowing a bucket load of baby gravy to be dumped onto ones face and mouth.
Anabel: Has anyone seen Craig?
Jared: yes, hes upstairs crawling the wall.
Anabel: crawl the wall? what do you mean?
Jared: hes single handidly turning his face into a glazed smeg doughnut