maybe something like an on/off fling or exes situation where they get along one second and bicker the next? maybe they had an awkward hand touching moment during a movie or fought over the arm rest and it turned into this whole thing but somehow it ended with them hitting it off by the end of it and ever since then they've always just sort of butted heads with each other so maybe there's a constant on/off tension between them? i'm up for anything though