She pulled off his left testicle with her bare hands and tried to swallow it, before spitting it out. A friend handed it back to Mr Jones saying: "That's yours."
Monti admitted wounding and attempted swallowing with intent and was jailed for two-and-a-half years.
Sentencing Judge Charles James said through bouts of sniggering and crossing his legs in sympathy it was "a very serious injury" and that Monti was not acting in self-defence.
Mr Jones had ended his long-term but "open relationship" with Monti towards the end of May last year. The pair remained on good terms.
After an argument ensued there was a struggle between them. In his statement, Mr Jones said she grabbed his genitals and "pulled hard and not in a good way."
He added: "That caused my underpants to come off and I found I was completely naked and in excruciating pain as I loved those Snoopy boxer shorts."
The court heard that a friend saw Monti put Mr Jones's testicle into her mouth and try to swallow it.
She choked and spat it back into her hand before the friend grabbed it and gave it back to Mr Jones. Doctors were unable to re-attach the partly chewed and mangled organ.
Mr Jones then said, "If she really loved me she would have swallowed."
Monti said she was sorry for what she had done. "It was never my intention to cause harm to Geoff and the fact that I have caused him injury will live with me forever. I am in no way a violent person."
"I have challenged myself to explain what has happened but still I just cannot remember. This has caused much anguish to me and will do for the rest of my life and I also hope that Geoff has learned that no one turns me down."
Old Knudsen a dating and relationship expert said: "I once had an 'open relationship.' I didn't find out until after the divorce."