Faking the call... shooting an angle?

[otnemem]

I need some opinons here - if your opponent makes a big raise on the river, and you grab your chips as you contemplate the call... then motion as if you're throwing in the call, but you keep the chips in your hand - is this an angle? Say you do this and your opponent says something like, "You got me," before he flips his hand? Is this an immoral play?