Sherri Shepherd's Ex -- She NEVER Sent Me Nude Pics ... But I Wish Sh

Lamar Sally insists he's NOT trying to hawk naked pics of his soon-to-be-ex Sherri Shepherd ... but tells TMZ if he did have nude pics of her, they might not be getting divorced.

Earlier this week a report came out that Sally had compromising pics of Shepherd and was willing to share them -- for a price -- but Sally tells TMZ that's complete BS.

In fact, he says ... "If Sherri would have been more sexual with me and sent me things like nude pictures, we'd still be married."

Sources close to the ex-couple tell us Sally hasn't heard a word from Shepherd since their surrogate gave birth last month to the baby boy they planned to raise together ... back when they were happily married. We're told the baby is living with Lamar in L.A. and Sherri's never met him.

We're told Sally rejected a $150K settlement offer from Shepherd in their child custody dispute ... because he crunched the numbers. That works out to $694/mo. over 18 years, and according to our sources ... Sally thinks the court will order Sherri to pay more..