I claim the ornamental design for a boxer shorts with pocket, as shown and described.
FIG. 1 is a front perspective view of the boxer shorts with pocket;
FIG. 2 is a front elevation view of the boxer shorts with pocket;
FIG. 3 is a rear elevation view of the boxer shorts with pocket;
FIG. 4 is a left side elevation view of the boxer shorts with pocket;
FIG. 5 is a right side elevation view of the boxer shorts with pocket;
FIG. 6 is a top plan view of the boxer shorts with pocket; and,
FIG. 7 is a bottom plan view of the boxer shorts with pocket.
The partial human figure shown in broken lines in FIG. 1 is environmental subject matter included to assist in depicting how the claimed design appears when worn, and forms no part of the claimed design. The remaining broken lines depict unclaimed features.