You don’t need to state “we like you, stupid! ” – But you really need to make it extremely clear there is interest. At the least to the stage where he can ask a male or friend that is female of if this is exactly what he thinks it really is.
But, from then on point, it really is all as much as him! Do not ask him down or perform some work with him after that. You just place a spark available to you, in which he has got to switch it into fire.