Yes I'm on mobile, I'm sorry. 

A little back-story: My biological father who was never there, ran off to another country to avoid paying child support. He'd come back here and there but always put any expenses on my mom or dad. 

Anyways, I recently had a baby, and I let my go on vacation with my mother and grandmother to their home country(to visit his great great grandparents). Where they were told to not let my bio father see the baby. We all hated him, so they agreed. 

 He texts me complaining, trying to guilt trip me, then tries to use my half sisters as leverage. (They live with him) He dodges any criticism I throw at him by saying that he was always there for me. I actually only seen him around a total of 16 times since he left after I was born,since he lives in another country. Anyways I cut him off completely from any social media. 

Okay back to now: He's sending me texts through my little sisters account pretending to be her. I know how she texts. She's 10. He keeps trying to get me to send pictures of my baby, pulling the "I'm your sister" card. Kinda insulting that he thinks I can't tell the difference. So I had to block her too unfortunately, even though it's technically not her texting me. 

Am I the asshole for blocking my sisters account because her dad is spamming me on it multiple times a day? 