The MC gets bullied by two girls and iirc one of his arms gets fractured. He decides to take revenge on them so he went to their mothers and revealed that their daughters are delinquents and they are the one who broke his arm. Then he blackmails both the MILFs and banged them and soon after he reveals to the bully daughters his relationship with their moms and then banged the OYAKODON duo and gets all of them pregnant. One panel I remember is when they told him they are pregnant by peeing on the pregnancy test strip in front of him. Let me know if you have name of this doujin.