Female

There's something graceful about the beast that makes you think she has to be female. She runs two tentacles slowly up the outside of your legs, then back down, then up the inside. Holding one of them between your thighs, its warm tingly gel tantalisingly close to your clit, she slowly drags the other up your body and across both nipples, then curls it around to undo the strap holding you up. You pitch forward, but she shoves the tentacle between your legs deep into your cunt, using it to hold you up while the other pulls something off the back of your neck... and suddenly, you can move.

The end of the tentacle in your cunt expands, pressing on all walls, until it can't be pulled out. Your new owner turns to leave the room, clearly intending to use the tentacle like a leash.