FIG. 1 is a top perspective view of a bottle cap showing my new design; FIG. 2 is a bottom view of the bottle cap as shown in FIG. 1; FIG. 3 is a top view of the bottle cap as shown in FIG. 1; FIG. 4 is a side view of the bottle cap as shown in FIG. 2; and, FIG. 5 is a side view of the bottle cap as shown in FIG. 3.