Mild vibration in groin (oo-er missus!) - any ideas?

[PunishmentRoundupWithJoon]

Have been having a low level buzzing/vibrating sensation around my groin for quite some time now. It was only yesterday I realised it was my body and not the furniture vibrating beneath me! It's extremely mild, and not in any way painful, and each 'buzz' lasts for only a second. Always in the exact same place.

Seems ridiculous that I've only just realised it's me, but previously I'd assumed it was my phone that was on the other side of the sofa, or if my phone wasn't handy, a vibration coming up from the flat beneath and causing the bed to vibrate!

Last night, lying in bed, I had a similar sensation in my big toe, What's going on??