I believe there is far more to this than meets the eye.
I agree with Lindy, that "sex" is being used as an excuse to cover up something else. Petraeus has bitten the bullet, taken the fall.
It could well be that Kelly is an agent of some foreign country. Broadwell is crazy, who knows what she was up to. The calls to Kelly are weird, there's something behind that.
It seems to me that "sex" was used as a way to get rid of Petraeus without a trial, wherein much more would be revealed. Someone is working very hard right now to keep the lid on, and all the cast on message.
I think.