I searched all over the internet but can't find anyone who has done this before. I'm moving into my friend's small guest house (it's basically a 10'x10' shed), and want to sleep on a twin bed to save space. However, I had the idea of using a sort of trundle and a second twin mattress to make a full-size bed for when my significant other sleeps over. All of the trundle beds and DIYs I've found all have the beds separated, one up high and one on the floor. Obviously, that will make things a little awkward for activities, so I'm trying to figure out a way they can both be on the same level.

So far, I figure I'm going to have to build some interlocking bed frame that can slide apart without actually coming apart, and I also want it to be a good 3-4' off the ground. I'm picking up a used wooden twin bed frame (ikea) that will hopefully give me a good starting point at least.

I'm just curious if anyone has ever tried to do this or even seen it done, or any advice that might be helpful. Thanks!