Context, 13 yo went to a friends "party" 2 weeks ago. I was away at the time and left arrangements to DS and DH. Turns out they didn't buy anything, even a card. I didn't realise this until this weekend, when it was DS's birthday. He recieves a card with a small token gift (joke). If it hadn't been for DSs birthday I would have bought a gift for the other 13 yo when I realised that we hadn't in fact given him anything, now I feel awkward about it. Should I just leave it, should I explain to his mother that I wasn't there or should I buy him something?