UGH, sometimes this Mom stuff really stinks

My oldest DS has been told that he is dangerously close to NOT coming on the TOAL with us. He's a smart kid, just ZERO motivation, scatterbrained and super laid back. He's dropped letter grades on his report cards because he "loses" or "doesn't remember" his homework. He actually sits down every night and DOES the silly work ... but then can't be bothered to turn it in.
Lately, he's been "stretching the truth" regarding his work and his homework. He's always been a really good kid and never given DH and I any real reason to doubt what he's telling us ... that is until NOW

I got a note from a teacher last night ... or should I say I FOUND the note in his backpack, he "forgot" to give it to me. He's failing Reading because he's missing 3 of 9 assignments that he told DH and I that he did at school and just turned in late
We laid down the law and made it clear in no uncertain terms ... that we are MORE than willing to take his cousin and leave his sorry self back home if he continues down this path. He's only 11 for crying out loud