as a birthday present to them?

http://static.guim.co.uk/sys-images/Guardian/Pix/pixies/2009/4/21/1240351813795/Charla-Muller-and-husband-001.jpg

Basically, as a birthday present the wife said to the husband that they should get it on once day guaranteed for 365 straight. Previously it was about once a month. Full article here:
http://www.guardian.co.uk/lifeandstyle/2009/apr/22/365-nights-charla-muller-sex