A Washington DC lawyer is suing his former fiancee over a $100,000 engagement ring that she refuses to return.

Ryan Strasser filed the lawsuit against his ex Sarah Jones Dickens Monday, referring to the four caret diamond ring as a 'conditional gift' and arguing it should therefore be returned since the marriage never happened.

The couple were set wed in January of this year, but broke off their 11-month engagement in a 'highly contentious breakup'.

Washington DC lawyer Ryan Strasser is suing his ex Sarah Jones Dickens, who has her Ph.D in art history

He is paying nearly $1,000 a month until 2020 for the four carat $100,000 ring

After a month of dating at the end of 2015, Dickens, who just received an art history Ph.D, was involved in a car accident.

The lawsuit claims she could not get back to North Carolina where she lived and instead moved into Strasser's condo in Virginia until her car was repaired.

That's when the couple decided to be in an exclusive relationship, the lawsuit states.

The couple ended their 11-month engagement and she refuses to return the ring

But the condo was too small for the couple and their three dogs, so in July 2016 they moved to a five-bedroom home in an affluence DC neighborhood.

Strasser rented the home, paying $4,800 per month and 'assumed the responsibilities of sole breadwinner', the lawsuit states.

Then within just months of being in their committed relationship, Dickens said 'she expected Mr Strasser to propose to her with an engagement ring within one year of the start of their relationship.'

Dickens allegedly had strict guidelines for the type of ring she wanted as well, that included it be between 3.5 and 5 carats 'with an inclusion rating of no ''worse'' than VS2 and a color rating of no 'worse' than G.'

The lawsuit claims Strasser did not want to spend more than $40,000 on the ring, but Dickens insisted 'that she deserved a large engagement ring because she did not believe in ''wasting'' money on a wedding and so the Parties should instead spend 'extra' on an engagement ring, something she would enjoy daily for the rest of her married life.'

He purchased the ring for $99,800 in February 2017, taking out a $30,000 loan will continue to pay $912.71 each month until 2020.

The lawsuit says the 4.06-carat diamond engagement ring was purchased 'in anticipation of marriage.'

An image of the refrigerator in their Washington DC apartment that Dickens allegedly turned off to let meat spoil

The apartment was left in more than $4,800 in damages which Strasser is also suing Dickens over

Less than a year after the proposal the couple broke up, ending their engagement.

Strasser moved out and continued to pay rent so Dickens could continue to live there.

The lawsuit says that after repeated requests and months of negotiating, Dickens finally agreed to 'return most but certainly not all of Mr Strasser's property remaining at the home.'

Strasser filed a lawsuit Monday claiming the ring was a 'conditional gift'

'She refused to return Mr Strasser's conditional gift of the engagement ring, as well as electronic equipment,' the document says.

In that time they had come to an agreement that Dickens would move out of the home after she finished her dissertation.

At some point, she allegedly changed her mind, proclaiming the engagement ring the 'belonged to her' forever, that she would 'never give it back,' that the 'deal was off.'

Dickens finally vacated the home without telling her ex and unplugged the refrigerator - leaving meats to rots and Strasser to pay for the damages, the suit claims.

It also says 'angry writings' in 'pen and permanent marker' were left on the walls.

The cost of damages exceeded his $4,800 security deposit.

'After repeated unsuccessful entreaties to her counsel to arrange for the return of these items, Mr. Strasser was left with no choice but to file this action for the return of his belongings and for injury to his leasehold tenancy caused by Defendant,' the suit claims.