Rainbow kiss is a slang term for a type of sexual activity. However, neither this question not its answer are suitable for all ages. And, some people would find this material objectionable.
As an expression "tube" is usually used as slang for television.
It is a teen slang description of a kiss.
it means "i agree" its an expression for pride
This is slang - it means your spouse.
The phrase "Mugging me" is slang for "Staring at". As in "Who you muggin?"
This is a slang expression for "sexual intercourse".
kiss it means... K EEP I T S IMPLE S TUPID
it means kiss -like mwahhh
cat is under the table
Old time expression for a big hit, a success.
To "french" (slang) is short for "french kiss" which means to kiss open-mouthed, using the tongue.
The meaning behind "xoxo" is "kiss-hug-kiss-hug", while "hth" could mean either "hope that helps" or "how the hell". Its possible that this slang term could also be referring to a webpage of the same name.