I'm not sure which is more stupid:
You thinking Europe has no problem with illegal immigration.
You thinking everyone in the 3rd world wants to come to America.
You thinking fundamentalists who make Santorum look pro-gay will enter into same-sex marriages.
You thinking it's somehow easier to enter a platonic marriage with someone of the same-sex than the opposite.
You thinking Obama "agreeing" with you makes your oppinion more legit.
You thinking Sweden is extreamly hard to travel to.
You thinking there are no bisexuals.
^^^^^^^^^^
In addition to all these points, not having gay marriage
increases the likelihood of strategic sham marriages. When gays feel they're never going to be able to get a "real" marriage, they're much more inclined to get a sham opposite-sex marriage to help a friend with immigration. I have personally seen this happen.