make-up sex

Ask her to wear costumes and/or masks when you guys do it. You can pretend they are different partners and you're 'catching up.'

With a little paste and kid-proof scissors make it into a grade-school art project - print out photos of the women you want to have slept with and glue them onto the masks. (If you have photos of these women's other distinguishing characteristics, feel free to explore other materials -- silly putty, that stuff they make kitchen gloves out of now, pencil erasers, etc -- for appropriate dress-up.)

Believe me, girls don't mind that stuff. They love arts and crafts.