@Bonnie-And-Sam0
Guys - a recipie for disaster all round. From slighly agressive pets, to grandchildren (who seem to be left at home alone with no supervision) through to wanting guests out of the house at random hours. I think I would be worried more about the safety of the guest!
Seriously though, it really won't work and will cause your friends a lot of stress, and your guests even more.
I'd look for another solution....why not take in a long term logder who will get used to the dogs and whom the parents can trust. Perhaps someone in their work circle, or friends of friends looking for a place, etc..