The spelling of the word "sleeping togethers" may seem confusing, but it can be broken down phonetically as /ˈsliːpɪŋ tʊˈɡɛðərz/. The first part, "sleeping," is spelled as expected, but the second part "togethers" adds complexity. The "t" and "h" merge to create the /ð/ sound and the final "s" is added for plurality. Thus, the correct spelling of "sleeping togethers" is without the apostrophe, despite the temptation to add one. This phrase refers to two or more individuals sleeping in the same bed.
The word "sleeping togethers" seems to be a combination of the words "sleeping" and "together" with the addition of the plural suffix "s". However, it is important to note that "sleeping togethers" is not a recognized term in standard English and does not have a widely known etymology. It is possible that the phrase has been coined or used in a specific context that might give it a different meaning or origin, but without further information, it is difficult to provide a more specific answer.