Not if you used the right amount of water. Because red lentils break down when they cook, they can be difficult to drain. The best way to cook red lentils is by using a small amount of water when cooking them, then adding more if it dries up. By the time the lentils are done they will have (hopefully!) absorbed it all. If you do have excess water, make sure to drain it using a fine mesh strainer, otherwise you might lose some of your lentils!