The Standing 69 is one of those sex positions that everyone thinks is a good idea but is nearly impossible.... without a swing. The good news is now you can give it a reasonable show. I am not going to lie, it is still not going to be easy. Put the seat up very high, have her sit in it and then slowly flip backwards with her legs going outsite of the support straps. This will probably require a dual hook swing and a ceiling mount. Any swing with a cross bar or mounted to a stand will probably be too low to get her high enough.