Oh god. PLEASE use a condom, and lube. LOTS of lube. PLEASE use lots and lots of lube. Start out slowly, and work up to it. DO NOT just ram your cock in without working up to it. And make sure to make sure she is enjoying it ... consider both her words and her actions, she might just be doing it to please you rather than actually getting anything out of it herself. You want her to be able to walk again, right? Good. Then PLEASE take it easy ...