The bright yellow paper cut to resemble a small cloud and outlined with black felt-pen, was inscribed with a simple message: "Call me yrr" followed by a phone number.
It was a message, said the teacher who found it in a classroom, from one of the 6000 girls who study in the Pahadi school building in Sangam Vihar in the morning shift, to one of the 4000 boys who study here in the afternoons.
At half past noon each day, the girls leave school under the watchful eyes of their teachers, and stream past the boys waiting to enter: a moment, students say, for a hurried exchange of glances – and phone numbers.
The proliferation of smartphones and cheap data-plans have distilled the "love-letter" down to its bare essentials - long notes filled with flowery prose have given way to slips of paper with a set of digits, say teachers who intercept these missives.
"The ways of communications have changed," said Gaurav Kumar, who teaches Class 11 and 12. "Students' exchange numbers and talk through Whatsapp to avoid being caught by teachers and parents."
Being in a relationship is not easy for a young person in Sangam Vihar. The current crop of teenagers and young adults is the first generation to come of age in the diverse, characteristically urban, social milieu produced by the settlement's twisting lanes where families from different castes and religions live in close proximity.
Their parents, by contrast, are still rooting in their sharply defined identities derived from the villages from where they migrated to Delhi in search of work.
While teachers and parents, in time-honoured fashion, continue to fuss over whether young love shall distract their wards from the pressing demands of school and syllabus, they are also worried that an ill-considered love affair could lay bare the fault-lines of caste and religion that continue to police the desires of young people.
The 16 year old boy in Class 11, once measured love by the number of Whatsapp contacts on his phone. All that changed two years ago when he proposed to his present girlfriend, outside the Shiv mandir near Neem Chowk.
She was not like the other girls he had dated, he said, seeking anonymity as his parents didn't know he was dating someone. She took four months to give him her Whatsapp contact.
"Earlier, I would talk to many girls and get selfies with them to impress my friends. It made me feel like I was a popular guy" he said. "But now I am committed and things are different."
They are now exclusive on messaging platforms: they video call on Whatsapp for hours on weekends and holidays, and try to bunk school to go on dates to one of Delhi's innumerable monuments because meeting inside Sangam Vihar is asking for trouble.
The rapid proliferation of smartphones and cheap data plans has transformed the dating in Sangam Vihar.
Another couple met at their tuition center. They are both in Class 12. She was impressed by his good looks and his knowledge of Accountancy, a subject she struggled with.
"I took his number to discuss Accountancy with him. Initially we only spoke about studies but slowly the conversation became more personal," she said. "We meet during tuitions and have been only on two dates. Meeting him feels good."
But there's a problem: She is Brahmin, while her boyfriend is Jain. An inter-caste love marriage, her parents have made clear, is out of the question. Her elder sister had an arranged marriage in the same caste and her parents intend to do the same with her when she finishes school.
Yet, even parental disapproval, girls say, is shaped by gender.
"Whenever we discuss inter-caste marriages at home, my parents give me sermons about preserving the family honour but no such thing is said to my brother," she said. "I can feel the burden of carrying the family honour on my shoulders."
The Class 11 student, has had a similar experience.
"As a boy and as long as I have a good job I can do anything without the worry of bringing shame to my family," he said. "My girlfriend's family is stuck on caste. She worries that her family's honour will be ruined if we have to run away to be together."
Manisha Priyam, an associate professor at National University of Educational Planning and Administration (NUEPA), said such friction between the younger generation and their parents is common in spaces like Sangam Vihar.
"The city is generally intolerant to the idea of a romantic relationship that challenges social boundaries, but in Sangam Vihar this is heightened. People are migrants and they have been uprooted from their homes, so they tend to hold on to their identities with more rigidity," said Priyam, whose research work focuses on Sangam Vihar. Another concern – particularly for parents of young women, Priyam said, is the ever-present fear of violence.
While Sangam Vihar's children are transcending boundaries of caste and religion, their parents worry about for their safety.
At five minutes past noon one afternoon, Savita Rani anxiously urged the driver of her auto-rickshaw to drive faster through the Tigri neighbourhood's congested streets.
Her husband, Rani said, was standing outside school and needed to leave for work. She was hurrying to take his place and stand guard till their daughter got done with school.
"A girl in my colony was pursued by a boy. She rejected him and he threw acid on her," Rani said. "If he is arrested it will take years for him to be punished. The girl won't get her face back."
Rani wakes up at 5 each morning to cook for her family before she leaves for Green Park where she works as a cook in three homes. Her husband has a similarly precarious job.
"We cannot keep spending half our day dropping her and picking her up from school," she said. "I would have liked her to study further but it is too risky."
Rani said she would pull her daughter out of school once she finishes Class 10.
Rani's fears, though exaggerated are not unfounded.
The Delhi Commission for Women (DCW) chief Swati Maliwal has visited many double shifted schools across the city after she received complaints of girls being harassed outside school. Education minister Manish Sisodia raised the same issue in his letter to the Lieutenant Governor while seeking more security outside the city's schools.
School counsellors acknowledge harassment is a problem, but say it can be resolved.
Pooja Bakshi Jaitley, a senior counsellor at Tagore International School, Vasant Vihar, recalls the case of a Class 11 student who fixated on a classmate.
"He would follow her everywhere. His father and the girls' parents approached us and we roped in a psychiatrist," she said. "We were worried that he might harm here. We intervened and now he doing much better."
Jaitley says that parents need to have an open mind while dealing with teenagers because it is better to be aware and intervene when things go out of hand than have children lie to you and get into trouble.
"Kids will find a way of doing what they want," she says.
Moving out of Sangam Vihar is a long-term plan from many residents, but escaping for a date for couple of hours on Valentine's Day was something they thought he could manage.
The plan was for her to come over to his house after both their parents left for work. She would change out her school uniform, they would hire an Uber to go to the Purana Qila, hang out for a few hours, and then Uber back home by lunchtime.
It was a perfect plan with each second accounted for, or so he thought.
But this year, February 14 was also Shivratri, so both sets of parents decided to stay home.
"She messaged at 7.30 am saying that her parents are home and are not letting her go out," he said. "We think they may have a hint."
The Uber was never hired, the Purana Qila was not visited But they continue to plot their quick getaway. "Maybe another day," he said.