Door duplication

I was building my home with double doors and from the inside I place my doors I went to break them (because I usually put them on from the outside for looks and I broke them both and ended up with..... Four doors? I messed around some more and when I hit the right door to break it it opens, if I hold my finger down and move to the left door and break it instead it gives me two doors, I can then keep holding or release my finger and break the other door, also giving me a second door. But the big problem I found is after I did this I can place single or double doors anywhere and break them to give me two doors