Your mobile phone beeps, you have received a text message.
It begins: "I swear, I will make sure I give you HIV..."
But it's not an abusive threat, it's a "romantic" text message copied from a book on sale all over Nigeria that professes to give young people the words they need to court the woman or man of their dreams.
"H is for Happiness and joy forever with an I: Incomparable love that will never V: Vanish until death do us part. I love you," the message concludes.
The book, called "Touching the heart through unforgettable text messages (vol.2)" is one of several on sale in markets around the country that give suggestions to tongue-tied young lovers.
Nigerians are compulsive text senders.
Corny "romantic" messages and jokes are constantly being sent, received and recycled.
Many men complain that women send them "hot" text messages, but all they really want is money, while women say they are pestered by men sending "romantic" texts when all their suitors really want is sex.
But the book's author, 33-year-old entrepreneur Femi Emmanuel, says he writes text messages for people who are too busy, or illiterate, to properly express what is in their hearts.
He is not married but says he sends "special" text messages to his girlfriend - original ones, not out of his books.
The sale of all four volumes has been such a success he has bought a car with the proceeds.
"People have really embraced the mobile phone here in Nigeria, but they may not be smart enough to know what to say in these kind of situations, or maybe they're too busy, running an office or whatever," he said.
He gets inspiration from Indian "Bollywood" films and Mexican or Nigerian soap operas.
"I was watching a Bollywood film and the main actor said to his female lead 'hey baby, I'm a crazy lover'," Mr Emmanuel told the BBC.
"I thought 'that's good,' I paused the DVD and copied down the subtitles."
The text message threatening HIV was inspired by watching a Nigerian film.
"In the film, a man threatened a woman with giving her HIV. I thought how could I turn this acronym into a message?"
"You could send the first sentence on its own," he says.
"You are putting them in suspense, to create fear, and then you follow up with the interpretation that will give them joy and happiness."
The BBC asked people on the streets of the capital Abuja what they thought of the message.
Ferdinand Nwonye, 36, a civil servant, said he thought the message was funny.
"The person would first be scared, and then as they went through it they would start laughing," he said.
He added that the text books are mostly used by teenagers.
"I like sending romantic texts to my wife, but I think of my own, I don't need one of these books."
But not everyone sees it that way.
Businesswoman Janet Babalola, 35, says she gets romantic text messages from her husband.
"But if I got something like that I would be shocked," she says.
Mr Emmanuel, who paid for his high school education by selling newspapers at the roadside, borrowed 75,000 naira ($637; £363) from his brother to publish the first book.
He sold thousands of copies in cities all over the country.
What may appear cheesy and ridiculous to western eyes may not be so creepy to Nigerians, says a well-known agony aunt.
Nana, who answers readers' questions about relationships in the Weekly Trust newspaper, says Nigerians might see the words differently to native speakers of English.
"I think this boy who wrote these texts is a bit of a poet," she says.
"A lot of us in this part of the world are translating in our heads constantly from our local languages to English."
"A lot of Nigerian languages don't have a difference between 'love' and 'like', so a lot of these messages will come across as a love proposition when what the sender really means is 'I like you'."
But the texts can also serve as "adverts" which people can use to attract attention to themselves, with seedy intent, she says.
"Many girls and boys too are out on the road looking for customers, and it is only natural that technology has made that a bit easier."