A would-be teenage terrorist declared her love for an Islamic State fighter after bonding over TV game show Deal Or No Deal, a court has heard.
Safaa Boular also allegedly fantasised about killing former US president Barack Obama during their blood-thirsty courtship, jurors were told.
She allegedly settled on a grenade and gun ambush at the British Museum after her fiance Naweed Hussain was killed in Syria before she could join him.
Last April, she passed the baton to her older sister Rizlaine, 21, after she was charged with planning to travel to IS territory for terrorism, the Old Bailey was told.
Boular was 17 when she and her older sister allegedly plotted an attack on London in coded conversations about an Alice In Wonderland-themed Mad Hatter's tea party.
Prosecutor Duncan Atkinson QC has told jurors that Boular chatted with Hussain on social media for three months before they declared their love for each other.
The barrister has claimed she to wanted to marry Hussain and then don a suicide belt so they could be martyrs together.
But Boular's lawyer, Joel Bennathan QC, has told jurors that she was just a child when Hussain, who was twice her age, "groomed" her.
On August 18 2016, the couple shared their enthusiasm for British television game shows before exchanging expressions of love, jurors heard.
Hussain said Deal Or No Deal was a "sik game" (sic).
He told her that "mums rule in da house" where Deal Or No Deal would be on, followed by The Chase.
Boular, who said she stayed in a lot, agreed her mum loved The Chase too and she would watch a celebrity couples show and then Family Fortunes.
Hussain sent her a heart emoji and Boular replied: "I love you too."
The IS fighter, who was in his 30s, called her his "princess" and "shexy" (sic) in light-hearted banter, littered with "LOLs".
Boular responded by saying: "Oh my gosh."
Two days earlier, they had fantasised about killing Mr Obama, jurors heard.
After exchanging pictures of a Kalashnikov rifle, grenades and a handgun, Hussain bragged about "our klash", saying it was "one of a kind".
Boular sent him a picture of Mr Obama in reply and asked: "So what, is it us Vs..."
Hussain replied "Yeah" and allegedly called the American politician a "filthy kalb" (Arabic for dog).
Asked how she would kill him "if u had da choice", Boular sent an image of an explosion and said "shake my hand with Mr President", the court heard.
She allegedly told him she wanted to achieve paradise in death "so bad".
Hussain said they would both "go forth one day" or she would fulfil her role as a fighter and "wife" and "raise lions".
Rizlaine Boular, of Clerkenwell, central London, has already admitted planning a knife attack on London and mother Mina Dich, 43, has pleaded guilty to assisting her, the jury was told.
But Safaa Boular, now 18, who lived at home with her mother in Vauxhall, south-west London, has denied two counts of preparing acts of terrorism.