... between 3 and 5. In other words, I am thinking of number 4, because I am pregnant with our fourth child! It was completely unplanned. But, then again, sex with 3 small children in the house always is: both you and your husband have to be both willing and able, the kids have to be either away or otherwise engaged, and you both have to master the stealth of ninjas, so that, should your children decide their otherwise engagement is no longer engaging and they desperately need to get your attention in that instant, you do not give away your location prematurely by panting or any other noise you would, under normal circumstances, love to hear from your partner and make yourself. And so, sex in our household has been AAA for many a year: accident, adventure and acrobatics. And all that application of imagination, inventiveness and creativity has another benefit - it will keep our minds sharp and Alzheimer's free!
If you are among those parents fortunate enough to have relatives within the 2-hour-drive radius or financial flexibility to afford a babysitter on regular basis, than you probably have no idea what I'm talking about :)
In any case, just when we got rid of diapers, gave away all the baby clothes and most of baby furniture and other accessories, we need them all again!