One reason why homosexual sex kills is because male homosexuals have an average of 1000 different sex partners a year. Many have more, many more.An average? Why don't these Olympian supermen control us all? Oh right, they already do :)
It puzzles me somewhat when the societal health risk argument due to homosexual promiscuity is advanced, yet simultaneously civil unions/marriage, which one would expect to reduce promiscuity, is advocated against.
I would suggest that the government get out of the marriage business. Let the churchs decide for themselves who gets the sanction of "their G-d(s).
A requirement to pay child support is in most states, uneffected by one's marital status at the time of the child's birth. Nor is your right to visitation affected by marital status.
The only disadvantage would be the high unemployment rates this would lead to divorce lawyers, and the expected bad things these charlatans could accomplish with their newly found spare times.