The red seal in our bottles is what seals the cap and the bottle together. It prevents lubricant from leaking out if the bottle tips over.
Do not throw away this seal. Simply remove the cap, poke a hole in the seal and screw the cap back on. Others prefer to simply remove the red plug and replace it when they are done using the bottle.
If the twist top is fully closed and the red seal is intact lubricant will not leak out.