What do you mean if .

Well I mean, my brain abnormalities would make more sense

"So thats why im messed up in the head"

It would explain my extreme distaste for them...

Feel disgusted by their choice

I would be kind of horrified. And annoyed and angry at their irresponsiblity for having kids (they don't make a good combination as it is, in my opinion).
And then I guess I'd pretty much accept it. What's done is done. There's nothing to be changed about it now.

Like a niece.

wouldn't care, it's a bit late for me to be shocked and appalled, they've done worse, and at this stage nothing done could be taken back anyhow. it'd be weird but oh well

appalled and offended

mine aren't tho

Betrayed

Wonderful.

Step I hope 🙄

Meh.

Aroused