365 - 062 It doesn't matter

Little Monkey goes to "p'ay out'ide". With his Lola backpack of course, he has some toys in there just in case. But "it do't madder"... Not sure why it doesn't matter? He says that all the time now. First time he used it was in a situation which made him sound very naughty. So I told him off, big time. Now I think he didn't mean it that way but I still have no clue what he means with it... Very confusing. Seems to be just a filler to say something.