Please help me find this book

[AJ2009]

I read a book I got from my Aunty over 20 years ago now.

It had a red and white page cover with I think an outline of a boy sitting on a wall but that could be a made up memory lol, but the colour was definitely red and white.

I remember a line in the book and I don't know why it stayed with me but it's about the boys Aunty having a balloon for a boob, I think she has breast cancer and told her nephew there was a balloon there now.
I think this boy hangs around with his friends daily.

Now This bit I don't know whether this was wrote in the books front cover by my Aunty or if it was a name in the book but I remember 'Toby'

I know it's a long shot but I keep remembering this book every few years and would like to read it again just to see what it was about!

I'd appreciate it if anyone knows

Any ideas

I haven't read it so not sure about the aunt/balloon part but maybe Paddy Clarke Ha Ha Ha by Roddy Doyle?

I think the plot may be similar but it's not that. Also I would know the cover straight away if I saw it it was fully red and white.

Thanks though