The Billy can be a bit narrow depth wise (35cm) best if it's 45 to 50cm. Detolf would be good
Or a bin cage? If your boyfriend needs convincing - it makes a great modern room display when sat on top of kallax units and makes very useful and attractive storage underneath - and it could look a bit like the first photo on here
(That is actually an expedit no longer made but similar to a detilf on top of kallax units).
https://www.google.co.uk/search?biw=...mg.eAhHexUhgX0