Can a couple take input (about Vacation plans) from a Co-worker without it being a 3rd Party Intrusion?

My girlfriend planned a trip to another city for the weekend. I came home with input from a coworker on what to do and see in our travel plans. My girlfriend said that we have to cancel the trip because it is bad karma now. She said getting input from others is a 3rd Party Intrusion especially if it's not a friend and we must cancel the entire trip.