Never buy a solid bed and mattress worth hundreds or even thousands of pounds or dollars.
When the man in the apartment next door starts playing his stereo at midnight the other side of your bedroom wall, it’s impossible to move your bed-monstrosity to the living room. However, if you had an airbed, then it could be simply up-ended and shifted next door, thereby ensuring a good night’s sleep and no nasty litigation from him if you complained about his noise, infringing his personal rights.
Incidentally, it will also encourage morality – observe the woman only able to read a brochure – any hint of hanky-panky and they’d both bounce off the airbed. The downside is that the heavier partner [possibly the male – I weighed in at 87kg the other day] has the lighter partner rolling down on top and incommoding him all night.
But I feel these are minor quibbles compared to the symbiosis and balance you’d develop in order to both stay afloat and not crash onto the hard floor. You’d learn teamwork and add interest to the hitherto relatively dull process of sleeping at night.