The summit is being held at "the luxury Lough Erne resort in Northern Ireland," and a Downing Street spokesperson says Cameron wants Obama and the other leaders to focus completely on issues like "[taxes], trade, and transparency," rather than their "wives and girlfriends."
Cameron says he got the idea from last year's G8 Summit at Camp David. That summit "was attended by the leaders alone."
This means the traditional "separate program for visiting wives" will not be prepared for this year's summit.
However, because Cameron is ultimately powerless in dictating whether leaders do or don't bring their wives and girlfriends, it is believed Mrs. Cameron may "host a modest lunch in Downing Street" if Michelle decides to come anyway.
In other words, stay home, Mrs. Obama!