In your defence, it seemed like a good idea at the time.
You and Wally decided to move in together, and you've quickly discovered that there is not enough room in this tiny apartment for everything you and Wally have. There's barely enough space for half of your books and posters, let alone Wally's posters and the souvenirs and trinkets he brings home after missions.
Neither of you wants to get rid of anything, but you don't have the space for everything. Damn you, maximalism — which is really just hoarding in disguise, not that either of you will ever say that out loud.
"What if we put up my posters for one day, then we put up yours the next? Same with all our other stuff. We could have alternating decor or something," Wally suggests, shrugging. He's trying so, so hard to make this less hellish for you both. It's not working.