In a small room at London’s Vault festival, drag king Christian Adore is trapped inside an imaginary dungeon. Clad in a sequined burgundy suit, he is taunted by drag queen Eaton Messe, who paces menacingly outside Christian’s pretend cell. This is Dragprov, a double act who improvise – in drag.

The pair are performing their latest impromptu musical, titled Lord Help Me, I’m in a Dungeon! With a live pianist, Dragprov perform songs and sketches that are quick-witted, eloquent and made up on the spur of the moment.

As with all Dragprov’s gigs, tonight’s performance is dictated by the crowd. As it’s Valentine’s Day, the duo also sing about one attendee’s declared love of masturbation, after serenading a couple about what they like and dislike about each other.

Most of Dragprov’s songs have a spoof Broadway feel, complete with synchronised dancing, harmonising and a bit of hip-hop. Eaton, wearing a lacy red dress, has a knack for cutting jokes. Christian is a sensitive but charming soul – and an excellent singer.

Dragprov are Francesca Forristal, 24, and Ed Scrivens, 28. We meet at the Horse & Stables pub, where Forristal is performing her solo show Oddball as part of Vault. Together, they are chatty and charismatic, finishing each other’s sentences and frequently breaking into song.

Facebook Twitter Pinterest The pair met at Oxford university where Scrivens is studying for a PhD in Egyptology. Photograph: Tatjana Terentjeva/Dragprov

They met in 2015 through an improv troupe, the Oxford Imps, while studying at Oxford University. (Scrivens is currently studying for a PhD in Egyptology there.) “We always really enjoyed performing together when we did improvised musicals,” explains Forristal. “We’d always end up doubling up and being a duo.” She pauses, before adding with a grin: “And, then, we were also both very gay.” Scrivens jokingly chimes in: “Yes, that is true. That came as less of a surprise to me than the improvised comedy.”

From there, says Forristal, it was a natural progression. Alongside improv, they both wanted to try drag. So, they started Dragprov a couple of years ago, recruiting pianists Tom Hodge and Jordan Clarke. They have developed distinct personae for their characters, citing queens such as Felix Le Freak and drag king collective Pecs as influences. Eaton, says Scrivens, is a “strange mix of haughtily disapproving, but also quite inherently silly.” Christian, explains Forristal, “likes everything that is glittery and has a lot of emotions and he wants to tell everyone all of them”.

With the bulk of their shows based on audience participation, they’ve had plenty of memorable moments. At one show in Newcastle, they ended up basing an entire musical, called There’s Nothing Here, on the concept of space. “The black hole learnt to love,” says Forristal. “It got deep.” On another occasion, Scrivens played a spirit of the forest named Stick.

How would they describe their act? “It’s a joyful romp,” says Scrivens. “A celebration of silliness and musicals and wit.” He describes his character, Eaton Messe, as “[Edmund] Blackadder in a frock,” while Forristal says Christian Adore is Baldrick. When I ask how much preparation goes into their shows, Forristal laughs heartily. Still, the pair say they get into character while getting ready and do some warm-up exercises.

Right now, the duo have a monthly show at the London Improv Theatre, alongside a residency at the Jericho Tavern in Oxford. Later this year, they will perform a family-friendly show at the Southbank’s Underbelly festival. Ultimately, though, they have no long-term plans. They’re simply two mates having a lot of fun. “It’s great that it’s doing so well, and we love that,” says Scrivens. “But we do it because we enjoy doing it.” Slipping into a funny voice, Forristal adds: “The second we get jaded, we’ll stop.”