Todd Palin is a Man and part eskimo. Sarah is often very busy with politics and away a lot. Casual sex does not have all the idiotic connotations with many eskimos as it does with wimps in business suits caught up with all sorts of fantasies.
In short, the eskimos can appreciate casual sex from a healthier perspective.
http://www.straightdope.com/columns/read/2066/do-eskimo-men-lend-their-wives-to-strangersThere is a difference between a Man just being a Man and a man who makes sex into a negative egoistic expression for example by taking advantage of interns for a BJ.