I have noticed that my oscar(vinny) and jd(jack) will cuddle with each other, the oscar will hover over the jd and vinny's bottom fin will rub on jack's upper fin. Other times the jd will charge at the oscar, as if he were gonna strike, the oscar doesn't move and jack will slow up and just rest his nose on the oscars side. It seems as though they enjoy each other's company, is this a normal behavior for fish, let alone two different types?