Since the beginning of time it's always been male and female.
Appeal to antiquity. We are not constrained by what was done in the past. Or else, we would still be dying in droves of diseases we now heal without issues.
They reproduce and have children and then it goes on.
Except for all those who do not and find other ways. Adoption is one example. Should we also forbid it, because it is not a simple biological equation?
If everybody was gay, none of us would be here.
There is a contradiction, there. First off, there are some gay men who sleep with women and have children. Second, the discussion is about preventing gay men from having children. So, why complain then that gay men cannot have children? Third, we are not all homosexual. There are enough heterosexuals to perpetuate the species. So, why repress the minority, when it does not endanger the rest?
You cannot sit here and tell me that isn't disgusting.
Appeal to emotion. There is enough materialon the Internetto show that heterosexuals can enjoy anal sex as well.
Do you see my point of view with all thus?
Yes, and I understand how emotionally stunted OP is, as a relationship, in his view, has to lead to reproduction. And yet, he fails to account for all the couples who cannot, for one reason or another, have children. Should they be barred from being together just because of that?
Humans have gone well beyond nature in building our societies. Why still keep to that particular limitation?