How old is your wife's brother and his girlfriend?

That could be a huge difference in how your FIL treated his daughter vs his son in regards to similar situations.

Plus there's also the fact that 'virginity rules' for dads are different between sons and daughters.

But in any case, I'd let go the comparisons. It will only make you bitter. Just better to focus on your situation only between you, your wife and her father/family and not include the brother.

The dad/family isn't so great.

Think about it. The FIL/MIL got pregnant at a young age. They obviously have issues regarding their own early pregnancy, yet BOTH of their children repeated the cycle.

You'd think that they'd sit down their kids and have the sex talk, talk about abstinence, birth control, the morning after pill, abortion, and adoption and their stance on all of them and disowning their kids BEFORE or as soon as the two of you met.

I think that is the issue I would have with them. They're basically shitty parents in this regard.

They knew exactly how it could go down, STILL chose to bury their heads in the sand, AND held their affections as a barganing tool to get what they wanted.

They're still winning. Kid is adopted out, daughter gets an education, married and a kid.

Part of me wonders what kind of grandparents they are for being so willing to give away their grandkid, but at the same time, blood is just blood and nothing else, but I've never had a kid.

Maybe FIL hated you so much that he couldn't stand to see the spawn of you that ruined his daughter's life, but you're still around and Spawn2 will be here so what did he prove?

I have no answers for you, but I feel for your situation.

I'm rooting for highschool sweethearts that stick together forever. Rarely happens, but I can hope.