Hi, my two 6 month old cats have been having a weird litterbox issue. Recently I I've been catching them urinating in the box together. A little background, I just finally managed to move both litterboxes to the basement. We have one large and one small one, and they both seem to prefer the big one (except Lily, who is fastidious sometimes likes separate boxes for #1 and #2). Both boxes are kept super clean.
Well, the last few days I went down there right before dinner and discovered them both voiding in the large box at the same time. Mind you, the second box is about three feet away. Neither of them covered, but neither of them seemed visibly upset by the other.
Can anybody give me a clue why this might be? Is this at all common with cats, and does it sound like there's any kind of behavioral issue or conflict I need to be aware of? My only alternative explanation for what it could be is that they know I'm about to lock them out of the basement for 5 minutes so I can prepare their food, so they wanted to hurry up and go, and they both wanted to go in the Big Box?
What the heck? Help!