Melania Geymonat, 28, and her girlfriend Chris were hospitalised with facial injuries and left covered with blood after the assault on 30 May.
The couple had been travelling home from West Hampstead to Camden Town after a date.
Four boys, two aged 16, one aged 15 and another aged 17, have been charged with an aggravated hate crime under the Public Order Act, Scotland Yard said on Thursday.
One of the 16-year-olds, from Wandsworth, south London, is also charged with theft and handling stolen goods, while the other, from the borough of Kensington and Chelsea, is accused of possessing cannabis.
The 15-year-old boy, also from Kensington and Chelsea, faces an additional charge of handling stolen goods.
All four are due to appear at Highbury Corner Youth Court on 21 August.
The group allegedly began harassing the two women when they discovered they were a couple, asking them to kiss and making sexual gestures.
We must have kissed or something because these guys came after us. I don’t remember if they were already there or if they got on after us,” Ms Geymonat said in a Facebook post.
“They described sexual positions ... the word ‘scissors’ stuck in my mind,” she added.
She said the attack escalated and the gang allegedly punched them both in the face until they were covered in blood.