Sherri Shepherd's Husband -- I Want Custody of Unborn Baby!

Sherri Shepherd and her husband have an unborn baby ... and he wants the kid. And here's the real twist ... she's not pregnant.

Sources connected with the couple tell TMZ ... Sherri and Lamar Sally have hired a surrogate who is carrying their baby, and the estimated delivery date is July 28th.

TMZ broke the story ... Lamar filed legal docs to end the marriage. The docs are for legal separation, but we're told the only reason the divorce box wasn't checked is because Lamar has only lived in California for 3 months and there's a 6 month residency requirement. He will change it to divorce in 3 months.

According to Lamar's legal docs, he wants full legal and physical custody of the unborn child, and wants Sherri to ONLY have visitation rights.

Sherri has not responded yet.

Lamar also wants spousal support and he wants the prenup invalidated based on FRAUD.