An added bonus to the obviously great gift idea: Sex on your partner's birthday is also a gift to yourself, says Michelle Hope , a sexologist in New York City. "Really think about how you can make it fun for your partner , and make it fun for yourself," Hope says. Gear up for the activities you know your partner loves, but also don't forget to include some of your favorites , too. 'Tis better to give and receive, if you think about it.