Double-Hauntings: How Were We Supposed To Know?

When I click on a double haunted house in my town I do not get twice the goo. Plus it doesn't tell me who visited. You need to click on an unhaunted building if you want friends to know your visiting. Otherwise it says haunted by ghosts. That's why it's good to know your neighbors and not pick up random invites. Everyday I'm visiting. I'm making my rounds to neighbors who I know visit and not only leaving goo but gremlins when I can.