An Old Bailey jury has been told of how a teenage girl, Safaa Boular, 18, sent Naweed Hussain an image of an explosion when he asked how she would kill the then US president.
Prosecutors say after he died in Syria before she could join him, she planned an attack at London’s British Museum.
Ms Boular of Vauxhall, south London, denies preparing acts of terrorism.
Her lawyer, Joel Bennathan QC, says she was “groomed to be radicalised” by her fiancé, and her family had encouraged and celebrated it.
‘Shake my hand’
Prosecutor Duncan Atkinson QC told the jury that Ms Boular was still 17 when she chatted online with Hussain over a three-month period.
She had to wanted to marry Hussain, who was in his 30s, and wear suicide belts together, he told the court.
Describing the online conversations between the pair, he said they had exchanged pictures of a Kalashnikov rifle, grenades and a handgun in August 2016.
The jury heard Ms Boular sent Hussain a picture of Mr Obama and asked “So what, is it us Vs…”
He allegedly replied “Yeah” and called Mr Obama a “filthy kalb” [Arabic for dog].
The prosecutor said Hussain asked how she would kill him “if u had da choice”, prompting Ms Boular to send the image of an explosion and say “shake my hand with Mr President”.
Two days later they declared their love for each other after talking about how they liked British television game shows Deal Or No Deal, The Chase and Family Fortunes, Mr Atkinson added.
‘Alice in Wonderland tea party’
The court heard Ms Boular decided to carry out a grenade and gun ambush on people at the British Museum after Hussain was killed.
But when Ms Boular was charged with planning to travel to IS territory, she is alleged to have encouraged her older sister to “carry the torch forward”.
The court heard that Rizlaine Boular, 21, of Clerkenwell, central London, has admitted planning a knife attack, while their mother Mina Dich, 43, has admitted assisting her.
In telephone calls to her sister from jail, Safaa Boular is alleged to have talked about an Alice in Wonderland-themed tea party – said by the prosecution to be code for the attack her sister was to carry out.
Based on her reconnaissance and discussion, it appears Rizlaine Boular planned a knife attack in Westminster, the prosecution says.
The trial continues.