Kris Humphries' Family -- Kim Kardashian Should Admit Marriage Was a 'Sham'

Kris Humphries' relatives have a major bone to pick with Kim Kardashian ... claiming Kim K's 72-day-marriage to the NBA star was nothing but a "sham" and it's about damn time she fess up to it.

Kris' aunt Dedria -- who attended K & K's wedding back in 2011 -- is adamant Kim duped her nephew into tying the knot as a ploy to boost ratings for "Keeping Up With the Kardashians," telling The UK Sun, "[The wedding] was a sham."

Not only that, Dedria says Kim needs to own up to her fraud so Kris can get the annulment he desires, explaining, "An annulment says it wasn’t valid in the first place. She should admit that it was a sham at the very least.”

As TMZ previously reported, Kim wants a simple divorce, but Kris is hell-bent on fighting for an annulment ... claiming he was defrauded, which could render any pre-nup illegitimate and free the NBA'er from his confidentiality clause.

That said, Kris' Uncle Mike believes his nephew's legal battle is motivated by revenge, telling the paper, "I believe he wants payback."