BDL stands for "Big Dick Lounge." When one is BDL'n (commonly used as the verb form of BDL) he is usually spending his time laying around smoking marijuana, eating chips or enjoying other sedentary activities with friends. If you're going to BDL, you shouldn't have any plans for the rest of the day, important business that would get in the way of your big dick lounging, or any worries on your mind. Remember, He who is BDL'n is comfy and confident.
It's raining out, looks like a BDL'n kind of day.