Maybe legal? Check it out: Common Law Marriage, Mortgage, and ociate Benefits Laws and Ethics?

I am part of a really strong friendship between me, a girl, and a guy who is in the military. Nothing ual, we have been neighbors since birth, we are practically related. Ever since my military friend left we have always wanted to pick up and move to him and follow him to wherever he is stationed. Us two that are left are basically fed by a silver spoon, so our part time jobs have helped us save some money up while living at home, but we still don't make enough to live on our own. His branch offers extra benefits if he were to get married such as increased pay, ability to live off base, and extra pay specifically to pay for rent and groceries. We can marry the girl with the military friend, but not really. With these benefits we would be able to all live together like the good ol' days. I am guessing that ethically this is wrong, but maybe not? I am more concerned with the legalities, is this possibly legal? Are there any loopholes? How easy would it be to pull off? Any additional comments/warnings/suggestions are welcomed. Thank you.