BBWcreator82:
Kidnapping a BBW/SSBBW wouldn't be so hard. Just woo them, offer to cook a meal at your house after a while.
They take the bait, then once you have them at your house just give them the tour and put them in your prepared fluffy dungeon and lock the door when they least expect it.
The trick is getting them to come to you. Work smarter, not harder.
Does it have to be a dungeon though?
At least Michael from Feed had Deidra in what looked to be his living room.
Then again, if you're trying to hide somebody, plain view may be not the greatest places.