Haha, we are all in the same boat. I've wondered this many times too. I've killed my fair share of nut butter tubs in the middle of the night. I have to have my wife put our nut butters in a lock box and hide them from me, otherwise I would screw my diet up every day, haha.
So, back to the original question... It's been my impression that the body simply can not digest all of that fat at once. However, I could be totally wrong.
Also, I much enjoy making my own nut butters. My favorite is coconut/macadamia nut butter. You just take the shredded unsweetened coconut a put it in the food processor for about 5 minutes or so. Adding a bit of coconut oil can help too. Then drop in the macadamia nuts and continue to process. Sometimes I'll throw in some liquid egg whites and vanilla protein powder... Maybe a little bit of walden farms 0 cal syrup.
Some of my other favorite combos are: walnut/macadamia/coconut, walnut/almond/pecan, walnut/macadamia/almond... really any combination is good... And on occasion, I will throw in some peanuts or cashews.