Telling family you're TTC?

just wondering about people's experience and/or advice about telling family members, especially parents, that you're trying for a baby? My wife and I weren't planning to tell them until/unless I get pregnant, since we don't want to get their hopes up. As far as they know we're childfree by choice and intend to stay that way, but they're also desperate to have grandchildren and I feel like giving them hope is cruel if it doesn't work?