Am I nasty,

My oh has his son this weekend and his grandad passed away 2 weeks ago and while he was away saying his goodbyes I took care of his son then last night he went to the pub for drinks with his family and asked me to have his son (I'd plans I cancelled) and I did! Then this morning because he doesn't want to get out of his bed he asked ms to get up with his son and after me saying no he needs to take responsibility of his own son he then used "im emotionally and physically drained" he's been fine asking his friends over! He expects me to get up every time his sons over, he never buys him new clothes or toys he'd rather eat out. I've bought all his clothes, he never wants to take him out only to his mums Because she'll look after him!? I only said I wasn't looking after him and I had him last night and last Sunday night too: I had work 3 x 12hr shifts and he's saying I'm a Nasty piece of work. Btw I know I took his son on and I don't mind HELPING but not doing all the work all the time while he lies on his ass. I'm only 22, I've give up alot but not good enough