Hear that, Pippa? Serena Williams invites Meghan Markle and 'plus one' Prince Harry to her wedding

There will be a role reversal in Prince Harry's relationship as the royal may be girlfriend Meghan Markle's "plus one" to Serena Williams' wedding later this year.

The 35-year-old American tennis champion is great friends with Suits actress Markle – often showing her public support for the budding humanitarian – recently tweeting her article on women's menstruation for Time magazine.

And unlike Pippa Middleton, who is rumoured to be finding excuses such as a "no ring, no bring" policy to ward off Markle and the media circus surrounding her and Harry's romance, Williams has no such fear of being upstaged.

The new royal pairing are said to be top VIP guests for the Wimbledon champion's eagerly-anticipated nuptials to boyfriend Alexis Ohanian – which will take place sometime this year.

"Serena has told her sister and some pro friends Meghan is definitely getting a "plus one" for Harry. Now the tennis players are even more desperate to ensure they score an invitation for themselves so they can party with royalty.

"No date has been announced yet but Serena has made it clear who should be keeping their diary free so they can celebrate her big day," a source told The Sun.

News that Markle and Harry might be the most high-profile guests at Williams' wedding comes just a few months after the tennis player announced her engagement to Reddit co-founder Ohanian.

She announced the great news on Reddit with a short poem after 15 months of dating Ohanian. In the poem, she claimed that her 33-year-old partner proposed at the place they first met during a surprise trip to Rome.

She wrote: "I came home/A little late/Someone had a bag packed for me/And a carriage waited. Destination: Rome/To escort me to my very own 'charming/Back to where our stars first collided/And now it was full circle/At the same table we first met by chance/But by choice/ Down on knee/He said 4 words/And I said yes."

Ohanian also made the engagement public on his Facebook page, according to CNN, with a link to Williams' Reddit post, writing: "She said yes."

The couple have kept their romance largely under wraps, despite a few Instagram posts, and are said to have begun dating in late 2015.

Williams and Ohanian's wedding will be the second nuptials Markle and Harry will attend as an official couple, as it is said that Middleton will not extend an invitation Harry's other half for her big day to hedge fund boss James Matthews on 20 May.

Earlier this month, Markle and Harry attended Tom "Skippy" Inskip and Lara Hughes-Young's wedding in Montego Bay, Jamaica, where the actress wore a pre-fall 2017 gown by duchess-favourite designer, Erdem, and a Cartier Love Bracelet presumably given to her by the prince.