The other tortoise flipping the other back over is probably just trying to ram the other out of its territory. Just make sure you separate them ASAP. Am I right to assume that they are testudos? Testudos are highly territorial. But again, just make sure you separate them as soon as you can, and have lots of hides and sight barriers. Further more, “cuddling” and “following” are just the two chasing/pushing each other out of their territory, and it is highly stressful for them to be together.
Yeah mine are spur-thighed, only had them a month now or just over. They are babies. My aim is for when they’re about 1-2 years old I will be separating them but can’t do that right now where I live. I am worried about that too, the territorial behaviour.
There are a ton of hiding places in my enclosure though and many things for them to do and at the moment they hardly ever bother each other, they don’t even sleep together, they both go in separate logs at night so I’m happy.
I am aware that this could change at any minute but for now I’m happy it’s going well.