I don't understand

I understand why children prefer Moms over Dads when sick or hurt.  Moms are softer, their faces are less prickly when kisses are administered, they have softer voices.  I understand why children prefer to sleep in their parents bed at night.  They feel warm, safe, and protected (the bed is probably nicer, too ;).  I even understand why children prefer eating out of my plate.  The food is much tastier on the adult side of the fence.  What I don't understand is why my children insist on having a preference for using my bathroom!  I must hear myself say "Hey!  go in your own bathroom!" at least 10 times a day.  I just don't get it!  I mean, it's the exact same toilet, just in another room.  Ours is not softer, less prickly, or warmer, and their bathroom is closer to their room where they sleep.  They bypass their own bathroom in the morning to use mine!!  Just a little while ago, Andrew came up to me and said, "Mom, are you almost done cleaning your toilet?"  "Almost, why?"  " 'cause I have to go to the bathroom."  "Go in yours."  "I'll just wait until you're done.".....seriously!?!?!  And, if by some odd chance, the person to whom the majestic throne belongs is actually using it, the same thing usually happens:  "can you hurry up, because I have to go really bad!"  "Go in your bathroom."  "I'll just wait until you're done."  Now really!  I asked Natalie once why they always use our bathroom, and she said "because it's closer to the kitchen."  I still don't get it.