Pictures emerged on Sunday of the pair on set as iconic love-struck couple Natalie and Prime Minister David.
Comic Relief director Emma Freud shared snaps of the two grinning with writer Richard Curtis as they shot scenes for the much-anticipated sequel.
The photos captured the perfect moment the duo reunited to act out scenes on the set of 10 Downing Street.
In a series of Tweets, Freud implied the characters were still together in the upcoming sketch.
She wrote on Twitter: “Our pm is still married. And she's still lovely.”
Snaps also appeared showing Grant, as David, addressing journalists at press conference during filming.
Actors including Colin Firth, Liam Neeson and Keira Knightley have signed up to return to the 10 minute short as well as Andrew Lincoln, Thomas Brodie-Sangster, Bill Nighy and Rowan Atkinson.
The 10 minute sequel will air on BBC One’s live Red Nose Day 2017 on March 24.