I have a very close relative who just did 23andMe testing a few months ago and found out that the man she thought was her Dad is not her Dad. Her Mom had an affair with a light-skinned Mexican guy. She looked different from her siblings, but none of her features were different enough that nobody suspected. It's kind of an awesome thing to find out because she never connected with her fake Dad. He's a jerk and she didn't live with him or see him much. Her biological Dad had been trying to reach her for a long time. He had even got a hold of her spouse before the DNA testing and it was ignored as a scam. Now that they've met, they keep in constant contact and he is so sweet to her. It's the craziest damn thing.
The story goes that she got drunk at the bar after she found out, comes home wasted and the conversation with her spouse went like this:
What's going on?
I'm a Mexican.
Huh? Like you drank tequila?
No. I'm a Mexican.