Can anyone help me remember the name of this book?

I remember the a lot about this book series but I cannot remember the name and I'd like to buy the whole set. I remember in the book, there's a girl named Nina who is allergic to cigarettes but insists on sucking on them. she likes a guy named Benjamin who is blind. but Benjamin likes nina's older sister claudia. on the spines of the books, in red they all say boyfriend/girlfriend, but I can't find anything by that series name. The books were published sometime before 2005 but after 1995. another thing I remember.. all the books have a cover that when all are together and open there's a picture of hearts on a brick wall with names in them, crossed out embellished...as if real teens were writing on the wall with spray paints. I had all but 3 of the 7 book series and during a move when I was a teenager, I lost them. now I'd like to find them again and buy them for when my kids are teens.