kissing kin vs kissing cousin

kissing kin and kissing cousin both are nouns.

Word	Noun	Adjective	Verb	Adverb
kissing kin	Yes	No	No	No
kissing cousin	Yes	No	No	No

As nouns, kissing kin and kissing cousin are synonyms defined as:

kissing kin and kissing cousin: a more or less distant relative; familiar enough to be greeted with a kiss

kissing kin (noun)	kissing cousin (noun)
a more or less distant relative; familiar enough to be greeted with a kiss	a more or less distant relative; familiar enough to be greeted with a kiss