This is not a SFW instance. NSFW communities will be tagged, and efforts will be made to keep SFW communities clean, but proceed at your own comfort level.
If we ignore the handle, the torus with a surface opening can be deformed continuously into an 8 shape, the lip of the mug is not a hole, but you can go down the lip of the mug, around the tube in the middle, and back out, a fully enclosed path
If we ignore the handle, the torus with a surface opening can be deformed continuously into an 8 shape, the lip of the mug is not a hole, but you can go down the lip of the mug, around the tube in the middle, and back out, a fully enclosed path