There are a lot of sensible areas of the body which are also erogenous zones (see Wikipedia). The neck is one of them. Stimulation can be achieved eg. by licking and kissing. The stimulation can be quite strong. So why not try to stimulate your neck with vibration? We think it works.
Think of an artistic designed necklace or collar with a vibration function. The vibration will be turned on when you move and gets more intense when you shake our head eg. while dancing. Or the vibration function will be turned on remotely by your friend.
Body interaction has made a 3d design for a vibrating necklace. It can be secured by a solid clip closure at the back of the neck. At this place the vibration motor is positioned which gives an intense vibration especially at the back of the neck but also at the whole neck.
The body interaction vibrator development board is inserted into the collar. It controls the vibration motor. The more you move the more it vibrates. There is also place for the battery. Wires and boards can be hidden. Unhidden it has a scifi look-alike.
Download 3d files from Thingiverse and print it.
Get the vibrating electronics from Tindie.
Edit and design your own with Tinkercad https://tinkercad.com/things/8stCwczMAkp