World Cup circa 2006. It's the new sideboob. Underboob (?). Basically, it's the sexiest part of your body to have on show this season, and it's all done without the use of boobs. Excellent. It's chic and understated, works well with skirts, denim, or in the form of a dress, and it has a retro appeal that feels ever so 1960s Milan. Pass me a coffee and some pizza, I'm down with this trend!
(OK, two are a little over £40, but with most super affordable from Missguided, I feel you can let me off this once)