Maybe I'm old-school but I think it's polite to say thank-you when you've done something for someone else. Especially with presents, it's good manners & shows appreciation, even if you secretly hate the item. One of my cousins had a baby, we're not super close but there are only 3 of us cousins in the family. I went out and bought a really pretty dress for the baby as a gift for the christening. (baby being christened at 1yo). I wasn't invited to the christening as it was just parents & best friends and I live miles away, so not worried about that. But I never heard back about whether the dress had even arrived in the post, never mind whether they liked it. Turns out they loved the dress so much, they used it as the christening gown. Aibu to be mildly pissed that they never said thank you for it?