The ornamental design for a lotionapplicator, as shown and described.
FIG. 1 is a perspective view of a lotion applicator showing my new design;
FIG. 2 is a front side view thereof;
FIG. 3 is a back side view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top side view thereof; and,
FIG. 7 is a bottom side view thereof.
Those portions of the figures that are presented in broken lines merely illustrate the environment of the design and are not part of the claimed design.