The ornamental design for a bead for use with string bikini top, as shown and described.
FIG. 1 is a perspective view of a bead for use with string bikini top showing my new design.
FIG. 2 is a front thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a side view thereof;
FIG. 5 is an opposite view thereof;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines in the drawings represent the strings of a string bikini top and form no part of the claimed design. The bead for use with string bikini top is used to secure the strings of a string bikini top, allowing the string bikini top to be worn in a number of ways.