The ornamental design for boots with a butterly, as shown and described.
FIG. 1 is a perspective front view of a right boot showing my new design;
FIG. 2 is a perspective rear view of the boot shown in FIG. 1;
FIG. 3 is a front view of the boot shown in FIG. 1;
FIG. 4 is a left side view of the boot shown in FIG. 1; and,
FIG. 5 is a right side view of the boot shown in FIG. 1.
All views of the left boot have been omitted from the drawings as they are mirror images of those of the right boot shown herein. The broken lines in the drawings form no part of the claimed design.