It may not be mentioned in the bible, but it is pretty obvious that God meant marriage to be between men and women. Otherwise he would have made Adam and Steve, not Adam and Eve.
1. You assume God exists
2. You assume He created Adam and Eve.
3. You assume he disapproves of homosexuality.
4. Your example is flawed, because if he did exist, as Christians define him, wouldn't create a generation without the ability to procreate.
5. The Christian definition of God included benevolence. Disapproving of homosexuality is contradictory because it shows a prejudice in God.
6. If God didn't accept homosexuality, he would create any homosexuals.
Never, ever, use fairy tales to support an argument.
Edit: It looks like other people already listed these things, but now they are nice and neat to display your lacking. Also, the bible was written by man, not god. Many Christians accept this.