Your "beginning" as you call it, is the core of the argument to me. Homosexuality, the same sex attraction of any species, is to most humans, dysfunctional, aberrant, wrong, f'd up, icky whatever you wanna call it. The fact that that two people sharing the same anomaly happen to meet one of their own is just coincidental.

Just like the man having sex with the picnic table making a way to sexually gratify himself that way is merely coincidental that the table happened to have such an "orifice".

It's no circle. It's pretty much cut and dry. The circle starts when people start trying to rationalize it as something other than what it is.