This is the same problem faced by a lot Giant Pandas in China! The Panda doctors are trying hard to make Panda couples to express their love to each other. But they seem disinterested. This is leading to the fall in the Panda population in China.
One fact has been established that Pandas can't/won't make love in Captiviy. When they are in the Privacy of a Bamboo forest...they have a better chance of courtship and love making.
So my advice would be, to go along with you wife to a Bamboo forest in Sichuan forest for a nice long honeymoon.