It is to my elderly aunt who sent a few bits and pieces for him with my parents at half-term. She usually comes with them but was not well enough to travel and we are all aware that she may not make the journey again (3.5 hours). 
I am extremely close to her and the dc both adore her. She is the most child-friendly person ever (no children of her own) and it has been lovely for me to see her with my dc and remember how she was with me when I was a child.
It is relevant to know that dc is a very strong writer and frequently gets certificates for his writing at school, on top table etc - it's not a struggle for him. Despite this he never wants to write at home. Luckily, the school is not big on homework, but if he does ever have any a huge tantrum ensues - until he actually starts it and then he gets into and enjoys it 
.
So I asked him to write his thank-you letter this afternoon and he came quite willingly. Ten minutes later he handed me this:
Dear X
Thank you for the thing you sent.
We went to London in half-term.
Forest won today!
Love from X
So no paragraphs, just a short list of rushed sentences. No asking after her, looking forward to seeing her etc (we do thank-you letters, he should know how to end them).
AiBU to have told him it wasn't good enough and that he has to do another one. He is screaming the house down, chuntering about 'a million sentences', 'ten hundred hours of writing' etc etc
I feel like crying - it is his utter selfishness that upsets me. He is usually lovely and commended for his sensitivity by teachers etc, so why can't he be arsed for his elderly relative?