MOTSS's an initialism used as a term to refer to "Member(s) of the Same Sex" or describe gay or bisexual encounters or relationships. It's possibly derived from the 1970 U.S. Census forms Member Of The Same Sex esp. one considered as a possible sexual partner, a potential or (less often) actual sex partner. For example, the term/phrase "on the down-low" or "on the DL" refers to men who've MOTSS experiences or occasionally sexually prefer MOTSS. Gay men or women prefer MOTSS exclusively. The inve… (More on Motss)