The two have used their assets as furniture in the past, though in very different ways:

Eden is involuntarily used as a display for various goth-themed accessories by her coworkers at Ghoul’s Edge, much to her continued annoyance. Kara also sometimes leans on her and stores items atop her rear whenever they’re out on the town, though Eden’s learned to tolerate it.

Mei on the other hand uses her mountainous mammaries to her advantage constantly. Most notably as a table or desk for reading or writing, and in some cases, she climbs up her vastness and has a portable bed! Though she only does it on rare occasions.