Tan Mom Patricia Krentcil -- I'm Divorcing My Small Penis'd Husband

Tan Mom's marriage is OVER -- and shockingly, she's the one calling it off -- this according to divorce docs filed in New Jersey and obtained by TMZ.

Just 3 weeks after Patricia Krentcil bitched about the size of her hubby's allegedly tiny penis during her disastrous stand-up comedy debut, Tan Mom has officially filed for divorce from Richard Krentcil.

Tan Mom tells TMZ ... she decided to call off the 8-year marriage because Richard recently failed a lie detector test about infidelity on a TV show called "The Test."

In the docs, Tan Mom demands $500 per week in spousal support PLUS $500 per week in child support so she can care for their 2 children. Tan Mom is also asking for full custody.

We spoke to Richard who tells us ... he wants to STAY with Patricia and hopes they can work out their issues.

He's got his work cut out for him, because in Tan Mom's stand-up act, she complained that her sex life was terrible -- "OK, let's have an orgasm, NOT!"