My brothers dad hits on me and tries to flirt with me

Yes. You read that right. My brother is adopted and got in touch with his bio dad and we all met him and he added all of us on Facebook.

It didn’t get weird until he started messaging me and hitting on me.

That’s weird bro. Your son is my brother. I’m your sons big sister. I’m 25 but also your SONS SISTER. This isn’t a thing dude. I’m disgusted. Like what do you even say to him!

He is also only like 8 years older than me, had my brother as a teenager but I feel like I am way too young for him.

Everytime he messages me “what you up to?” After liking my pictures I just wanna be like “kid stuff. Like usual kids.” But I can’t because I’m literally a grown ass adult that takes care of herself.

Everytime he tries to flirt I want to yeet myself out of a window. I’m just going to delete him.