Right, I agree that if the genes which predispose somebody to being gay had no benefits whatsoever, then they could not even exist; they would have a purely negative effect on fitness. So they must have some positive effect on genetic fitness to even exist at all. And they must be relatively significant and intractable from the side effect that some of their carriers turn out gay, given how common gay people are.

But that is separate from whether or not pressure from relatives to reproduce can be used as a mitigating strategy for the cases where these genes do result in someone being gay. And this strategy, then, would lower the amount of fitness those genes would need to provide to be viable.