Assuming she doesn't mean doing the dirty in between parked cars, is she on about her wearing boots while you're between her legs, or that the guy can hump her boots while she's wearing them?
She doesn't have Foot Worship listed on her 'Enjoys' list.
Update...
Just looked it up... Spanish Sex is same as a titwank according to Urban Dictionary. Typo
Shame, I like the idea of sticking my cock between a sexy pair of booted legs on a sexy lady