I know of only 6 two pilot marriages all but one including my own have ended not just in divorce but in very costly and nasty divorces. The principle culprit in all 5 divorces was the inability to negotiate and reach compromise. My own ex-wife stated during conselling that every thing would have been fine if I just did what she said, and that it was my job to do all the changes that were necessary because she just could not be wrong.
Two type A personalities in one house just did not work for me or my other 4 friends.
The one remaining marriage is in no way a happy affair. The wife also at the big U sleeps with everybody she can, and the husband is pretty happy not to have to climb that mountain. He has a rather slutty F/A that takes up his attention span. They probably will never get a divorce because they have seen the financial disaster that the others have suffered.