Prince Harry and Pippa Middleton may be sharing more than brother, sister-in-law love, amid speculation a romance could be budding because they are spending so much time together.

Since Pippa’s sister Kate Middleton married Harry’s brother Prince William, Harry and Pippa have reportedly met a handful of times and have nicknames for each other.

Pippa apparently calls the Harry “Captain,”  an endearing reference to his military rank, while he calls her “Commando,” a racy reference to rumors that she went without underwear at her sister’s wedding, according to London’s Daily Mail.

Although the Pippa nickname sounds far fetched, Harry reportedly ended his best man’s speech with the jest: “Pippa, call me.”

The two siblings-in-law also share something else. Both are going through breakups.

“They speak on the phone all the time and have met up at least five times since the wedding, once for tea at his Clarence House apartments… She thinks he’s got a really cheeky sense of humor,” a royal source told Grazia.

If so, that could support his choosing “Commando” as her nickname.

They were also spotted at the trendy Troubadour in Chelsea where they talked quietly for more than two hours.

“He only recently came out of a relationship, of course. He’s been trying to cheer Pippa up,” another source said. “We wouldn’t expect anything less from the perfect gentleman.”

If there is a budding relationship, would it be kind of creepy? Such brother-sister marriages are known to happen.

Weighing against a possible relationship is Pippa’s long list of other suitors.

They included supposedly jilted boyfriend Alex Loudon and George Percy, who also claims royal blood and comes from a wealthy UK family.

Still, being second in line to the throne can’t be a bad gig, especially when your sister is first in line.