First of all, cute avatar.
Second, I don't really use it much outside of stories and immersion. The relationship bonuses don't mean much to me, since relationships are super easy to cultivate in this game. So I mostly use it for stories - the young and unmarried couple like to WooHoo a lot, the old married could will WooHoo when they want to celebrate something or have a baby. One sim might like to WooHo anyone he can. I prefer to focus on skill-building and careers, but WooHooing can be integral to shaping my sims' personalities and lifestyles.
