This shouldn't bother me, but it does.
Friends of ours had their second child two months ago. A few months before that, I wrote to the husband of the pair and asked if his wife would want our ErgoBaby carrier. I knew she loved to wear the first boy, and since I wasn't using it (Ebay prefers the Kelty backpack) I thought someone could get some good use out of the thing on which I spent $150, which is no small purchase in our piss-poor family. He asked her, she said yes, and I mailed it off to them.
In the hundreds of photos she's shared on her FB page, the baby is in the stroller, in the carseat, in a sling, on a blanket, in their arms, but not a single picture is in the Ergo. They're not using it at all.
Would it be rude of me to ask for it back if it's not being used, because now I have other friends who are expecting and would love to have this thing? Or shall I just bite my tongue and wait it out in case they're just holding onto it for when the baby's older? I mean, you don't exactly call up your friend and ask "Hey, how's that expensive thing I gave you for your baby working out? Getting my money's worth out of it?" I wouldn't even ask that of my best friend.