We pray over each meal, as a family. When guests are over, what is the right thing to do? Still pray? Ask guest to lead the prayer? Don’t pray at all?
If it’s your tradition to say grace before a meal, then you should absolutely do it when you have guests. I wouldn’t ask them to lead the prayer without a little warning first, so they have a moment to think about what they’d like to say (or to give them the chance to say they’d rather not lead the prayer). I’ve always found it to be a welcoming and loving thing, to be included in a family’s dinner blessing, whatever their faith.