So I've been DMing a 5e game lvl 1-3 so far. And I have a question about stealth for my rogue. My player has been hiding behind/stealthing behind another PC.
So this is what usually happens. PCs bust into a room, and the enemies see him. The rogue makes a stealth check and hides behind a PC as a bonus action, then attacks from stealth and gets sneak attack. He will do this every round. I do try to do Perception for the NPCs, but they fail. So he basically disappears for the whole encounter.
So then he attacks cause he is fully hidden and gets a sneak attack every time. This seems OP!! I thought you could only hide in full cover. I know the Skulker feat allows a player to hide in partial cover, which I looked up. Hiding behind a PC of medium size only allows partial cover. Please help me! I just wanna make sure I'm doing this right and I hate players who take advantage of a loop hole.