The word 'unzertrennlich' translates from German as 'inseparable', so I've done this drabble based around the English translation.
Unzertrennlich - Revolverheld
When they were young, Aaron and Reid had been inseparable. They'd drifted apart as they had grown older and found other friends. But now they were growing closer again. Not in the same way though; it was completely different.
Caleb first noticed it at a party. Aaron and Reid had been standing next to each other. With anybody else, this would have been considered irrelevant, but, with Aaron and Reid, it was a miracle.
The next time Caleb noticed it was at school. Aaron had been standing if front of his locker, talking to Reid. Not yelling, or shouting, or arguing, but talking. Civilly. Caleb had been so shocked that he hadn't looked where he was going and ended up bumping into Kate, who had been walking in the opposite direction. By the time he'd apologised, Reid had gone, leaving Aaron alone and leaving Caleb to question whether he'd been hallucinating or not.
The third time Caleb noticed it was the most decisive. It was at another party. Caleb wasn't drunk, and he was pretty sure that Reid and Aaron weren't either. But they were kissing. On a sofa. And no one except Caleb seemed to have noticed or seemed to care. Caleb could only guess that this was not an irregular occurrence at parties. They broke apart and Reid caught Caleb's eye. And winked. Then returned to kissing Aaron. Caleb stood for a second, then smiled. Reid's relationship with Aaron had come in a full circle. From being inseparable to being enemies and now back to being inseparable again. And Caleb supposed it made sense.