I haven't started my multi engined training yet, but I've looked ahead at the theory.
According to that you would not maintain wings level, instead you would bank towards the operating engine so that the horizontal component of the lift counteracts the asymmetric thrust without need for rudder input. This is of course after you have the aircraft stablised, not immediately on failure. Then you would have no sideslip but you instruments would indicate that you have a slip towards the operating engine.
I don't know what the answer to OP's question would be though, since the horizontal component would only cause an indication of slip, not actual slip.