I looked after two beautiful glass ornaments for an old friend while he worked abroad. I have had them on display at my home for about 15 years. We used to be very close (not romantically) and are still in touch - Xmas cards etc - but don't meet very often. I have mentioned the ornaments to him occasionally, but as I haven't actually seen him I have never got round to returning them. He has never raised the topic with me. I feel a bit guilty for keeping them, but I can't tell if he cares or if he's forgotten about them. Should I make an effort to give them back?