So this is just a musing and I plan on getting AP for my fiance when he gets here and we get married... BUT, since he is from the UK and they are on the VWP would he for sure be turned away if he left the US without AP once married and without the AOS approval yet? TO be clear I am going to apply for this, but was wondering if anyone had gotten back in without it?

When he leaves without advance parole he abandons his Adjustment of Status.

No reason why he can not enter subsequently on the VWP, it would be a good idea to take plenty of evidence with him of his non immigrant intent.

Thanks, just curious how the hole thing worked. Didnt know if stuff got scanned into the computer and it popped up or what! I'm too nosey and like to know how all that stuff works. Totally a hypothetial question!!

Let me get this straight,

1. K1 is obtained visa and finance enters
2. Spouse leaves country before or during the AOS process without AP

they would probably be stopped coming back into the country.

Yes they do type all that stuff in to the data bases.

IMO, it would be best for AOS beneficiaries (except those on H1-b's--as they can use the original or extended H1-b AS EAD and AP document equivalent) to AVOID making trips outside US until either:

• AP is in hand (or renewed AP, if necessary)
• AOS is complete