Three characters. 没 (no), you know this one关 (close) is the fire symbol with two lids on top of it to close the fire (as in, put it out)系 (tie (verb)); somebody is tied down on a bed here. It's not my thing, but hey, don't kink-shame. To each their own.So no-close-tie means, no need to tie this up all neatly, nevermind.