I didn't actually say "I'm afraid that won't be possible", but it boiled down to the same thing.
A family member dropped by for a surprise visit, and I had been cleaning up a bit. Things that aren't normally lying around were out in plain view, one of which being a small tin of four drink coasters with cartoon characters on them.
This family member had his kids with him, one almost three and one a baby, and the toddler was playing with the coasters. I was fine with that; it kept her entertained, and there isn't much she could do to hurt those. When it was time for them to go, I told the toddler that it was "time to clean up", and she happily complied, putting the coasters back in the tin, one-by-one. Her father then said, "These are a little cartoony for you, aren't they? Why don't you let my kids have them?" He was serious.
I told him, "Because they're a collector's item, and I still use them." By this time the toddler was messing around with something else, and hadn't been paying attention to the conversation, so she wasn't upset by this. He let the matter drop, but he seemed annoyed. I was rather annoyed that he would ask for them, but nothing else came of it. My mom, who had been present the whole time but said nothing, thought I handled it well.