Alright I dont remember what it's called but in this Dean is Sam's master , and cas has a family but in his opinion he is learning "stuff" from Dean who lets him cane Sam tied to a wooden table I think..then Sam takes revenge on Cas but it turns out dean was just testing him ...then Dean and Sam take Cas as a slave and Sam is already Dean's slave ...I think there is also a scene involved where Cas is drugged by mixing something in his tea??
Thank you in advance!