Toilet training Puppy Chihuahua?

[psylent]

Our Chihuahua is now about 4 months old, i am at my wits end, if i step in another mess or puddle i am going to have a mental breakdown. He has his bed next to me by day (i work from home on my computer) and after hes had a long nap i take him outside and he usually does his mess, anytime its been a long time since he went i take him out, sometimes he will go out on his own (we have a puppy door) but if i am not watching he will go right behind me on the floor, in the kitchen, in the hallway, anywhere, it doesnt matter so long as i dont see (i can get enthralled in my work) i try to watch him like a hawk but hes like a ninja! If i see him get up and slink away i know what hes doing and i sneak after him to see, sure enough hes sniffing the floor in my house about to go!! he sees me notice him and he skulks outside and does it. how do you train a dog that is so snaeky on purpose! its like hes too lazy to go out! i cant take it anymore.. i had no idea a dog could pee like 25 times a day
oh i should add that he wont go in the same place twice (unlike most dogs from what ive read) which makes the litter box thing no good.