I'm sure this has been done to death but:
Our friends have (unbeknownst to them) used our favourite and quite unusual boy's name. We've both been ttc for a while and been supporting each other through it.
Would it be terrible if we still used the name? It would likely be the same name but we would choose to generally shorten it and they wouldn't, and I would ask them first if they minded and accept their answer. How would you respond?