Although women keep asserting that seeing a penis does not stir them, I have experienced otherwise.
On more than one occasion, initially composed females have become quite pliable once encountering me in the buff.
The trick is of course to bring this about with a certain finesse. Simply presenting an appendage is sure to embarrass and lead nowhere.
For me, things have so far worked out best traditionally in relaxed settings with a bit of alcohol present. Once I was having some drinks with a fellow student from France in her apartment in Phoenix, and as the conversation flowed from analysing American versus European denim cuts to why they might be different, and how circumcised American penises may need the extra space, demonstration time came soon, and things went straight to bed from there.