I wouldn't wander too off the beaten path. She's your wife and is asking you to respect some of her boundaries. She obivously cares more about you then just being an F partner. One night stands are not romantic, they are just lusty desire.
Can ya'll do a pretend hour and then you can get your rocks off too.
Pretend she has multiple personalities. Your wife is the nice, mature one, and her other side is a ****. When the **** comes out, enjoy it, but don't disrespect your wife afterwards. That way you can have your cake and eat it too.
Oh and listen to the song "Volvo Driving Soccer Mom" by Everclear.