The novelist and musician join Annie and Nick for the annual Sidetracked Christmas gathering, recorded at an Irish pub in north London.
The singer wore the pink jacket at Brighton Pride in support of trans women, says an organisation.
The superstar relives the surreal moment with Nadia Jae on Radio 1Xtra.
Radio 2's Scott Mills asks the US superstar if she would ever take a similar trip.
The five-time Grammy winner headlined the Brighton Pride event in Preston Park on Saturday.
About 300,000 people flocked to the city for this year’s Brighton Pride celebrations.
Mariah Carey headlined the first night of the Pride on the Park festival at Brighton Pride.
Thousands of people will take part in Brighton Pride's parade, street party and Pride on the Park.
The American singer is the headline act for Brighton Pride in Preston Park on Saturday night.
