Boris Johnson announced Saturday that he would be marrying his partner Carrie Symonds and that the couple is expecting their first child early this summer.

Johnson will become the first British Prime Minister in roughly 250 years to marry while holding the office. Symonds, meanwhile, is the first partner of a PM to reside at 10 Downing Street while not being married.

Symonds, 31, is much younger than Johnson, 55. Johnson has been married three times and has four grown children with his second wife, Marina Wheeler. This is the first marriage for Symonds, who previously served as head of communications for the Conservative Party until 2018 and campaigned for Johnson in 2010 when he ran for mayor of London.

“I wouldn’t normally post this kind of thing on here but I wanted my friends to find out from me,” Symonds said in an Instagram post. “Many of you already know but for my friends that still don’t we got engaged at the end of last year… and we’ve got a baby hatching in the early summer. Feel incredibly blessed.”

Symonds is the daughter of Matthew Symonds, who co-founded “The Independent” newspaper in 1986, and Josephine McAffe, a lawyer. She departed her Conservative Party position in August 2018, reportedly due to her relationship with Johnson becoming public. Since then, she has taken on a senior advisor role with Oceania, a charitable organization dedicated to cleaning up the ocean. Symonds’ role is specifically focused on plastic-reduction initiatives.

In 2007, Symonds became embroiled in the crimes of the convicted rapist John Worboys. Known as the “Black Cab Rapist,” Worboys would pick up women while operating as a taxi driver and pretend to be celebrating some sort of windfall, a pretense he used to offer them spiked alcoholic drinks. Once the drugs took effect, he would sexually assault them.

Symonds, who was 19 at the time, encountered Worboys after leaving a nightclub. She partook of the drinks he offered her, which caused her to vomit later at her home and pass out until 3 p.m. the following day. Symonds was among the 14 women to testify against Worboys.

Boris Johnson arrived in Manchester for the Conservative party conference with his partner Carrie Symonds
Boris Johnson arrived in Manchester for the Conservative party conference with his partner Carrie Symonds AFP / Oli SCARFF