OK most likely asked more than once… But did Luffy ever have learned the fact that Sogeking is Usopp. Usopp yelled it to him at the apologize... But do you think Luffy was aware of it even before at Merry's funeral? He actually said that Usopp isn't around... Which back than was actually stupid cuz he knew Usopp has jumped on board
Pretty sure he never found out and if I remember correctly Sniper King told Luffy that Usopp just left, that was right before !erry's funeral.