Playing fake husband is NOT acceptable!
Theres no excuse to him allowing Vinu to be pp's son and if he chooses to do so because nVinu is attached then he should sacrifice and be kaka to his son. Because if he meant what he said about him and Sai being parents to their children then without Sai he cannot be dad, unless its as a single dad. Is he going to confuse/cheat his child saying he's dad, pp is mom but they arent really married. Will he even tell Vinu who his real mom is?!
Best plot would be to have pp run with Vinu. Because that will show everyone she wasnt trustworthy and Sai was right to not want her out on bail also and near her baby.
Plus V deserves to be separated from both Sai n Vinu for a bit. If Sai is gonna be alone, v should also suffer. He cant be happy family playing ghar ghar.
After everything PP has done to Sai, V trusting her again, letting her into his life and defying Sai's last wish before she goes dead/missing to not let Vinu be with pp - all this is betrayal. Its an insult.