Can't you just say you're going and then not go? They're not going to know if you got on the flight, or if you were denied. If you're denied you'll never get past immigration and -- if they're meeting you there -- they'll never get past immigration in the other direction. Now sometimes immigration will inform people waiting that you've been denied but it's not mandatory as far as I know.
This doesn't work if someone is travelling with you, or if they're paying for the flights because of the issue below.
Your other problem is that the airline will be charged for your return flight (and, probably, fined) they may very well try and get this money back from you and/or whoever paid for the flights. If they have any indication you planned it they will definitely try and get the money and may get legal on you. Potentially they could blacklist you to prevent you flying with them (and maybe even their partners).
You could definitely use Karlson's suggestion and say you're being forced against your will to enter the country. But that might cause legal issues for your friends and family. You could be brutally honest and explain that you're worried you'll be compelled to overstay, that should be enough for them to flag you but it really depends.
The other suggestion in the comment, get your husband deported, is good too. Although it might be obvious (to him) that tip came from you.
In any case, you definitely don't want to directly lie to anyone or break any laws. The very fact that you know you're going to attempt this is a lie-of-omission when you board the plane.
I would very strongly recommend you do not try to do this -- it's of dubious legality, it's almost certainly going to annoy the airline if it works, and it may or may not cause problems for your family in the US.
Also, what if you "lost" your passport? You'd need to reapply for a visa at the US Embassy, and if you tell them that you'll be coerced to overstay it, you'll most likely get your visa application denied.
– Magnus Nordlander Feb 27 '14 at 13:25If that's going to work well with your family situation on the other hand, I don't know.
– Magnus Nordlander Feb 27 '14 at 13:33Both of these are immoral acts. Since you say you have a schengen visa, would it be possible to travel to a country in the schengen area where these acts are illegal and go to the police there? You say you don't want to get the family into trouble but that have already committed crimes against you. And you are not in Pakistan any more - you don't have to put up with these crimes. Though spain does not have a forced marriage law, there are EU countries that do.
– bloopletech Feb 27 '14 at 13:53You can make yourself not legally able to remain in the US, and yet still leave on good terms.
– Chris Travers Feb 27 '14 at 15:18