We claim the ornamental design for a lip balm dispenser, as shown and described.
FIG. 1 is a top front perspective view of the lip balm dispenser, in a closed condition;
FIG. 2 is a top front perspective view thereof, in an open condition;
FIG. 3 is a left side elevation view thereof;
FIG. 4 is a right side elevation view thereof;
FIG. 5 is a rear elevation view thereof;
FIG. 6 is a front elevation view thereof;
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken lines in the drawings showing the lip balm dispenser illustrate the portions of the lip balm dispenser that form no part of the claimed design.