[Anechoic]

My brother married a woman from South America (legitimately out of love). When she applied for citizenship, both she and my brother were required to sign forms (under pains and penalties of perjury) that the marriage was kosher, BCIS required references from friends and family (again, under pains and penalties of perjury) attesting to the legitimacy of the marriage, they had to deal with unannounced visits and constantly having to check in. It wasn't until the second kid came along that the govt finally seemed to accept the marriage as real.

Given the hoops my brother and sister-and-law had to go through, I think faking a marriage is a really bad idea unless the fake-spouse is willing to put themselves and close friends/family into big trouble if the sham marriage gets exposed.