Kenyan women's groups started the boycott in an effort to end the feud between the factions led by Mr. Odinga and President Mwai Kibaki that has paralyzed Kenya's government for weeks. Kenya's Federation of Women Lawyers has urged the wives of both leaders to withold sex from their husbands until the feud is resolved. The president of the group told the BBC: 

"Great decisions are made during pillow talk, so we are asking the two
ladies at that intimate moment to ask their husbands: 'Darling can you
do something for Kenya?'"

The group has also said it's willing to pay prostitutes in order to make the ban more effective. No word yet on whether Kibaki's notoriously short-tempered wife Lucy will join the movement.

Kenyans have many good reasons to want the feud resolved, but I suspect that no longer having to hear allusions to Mwai Kibaki's sex life should be reason enough by itself. 

http://blog.foreignpolicy.com/posts/2009/05/01/kenyan_pms_wife_joins_sex_boycott