The ornamental design for a bluetoothheadset, as shown and described.
FIG. 1 is a perspective view of a bluetooth headset showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left elevational view thereof;
FIG. 5 is a right elevational view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is a reference view of the bluetooth headset in accordance with my design, shown in its environment thereof.
The broken lines shown in the figures are directed to portions of the bluetooth headset and the environment of the bluetooth headset. The broken lines form no part of the claimed design.