You shouldn't enter someone's house unannounced.
Paul is driving through  a town on his vacation and decides to visit his friends Bob and Judy.
Paul wants to see his friends for the first time in a while.
Paul decides to call Bob and Judy to see if they are free.
Paul shows up unannounced and enters the house to find Bob and Judt being intimate.
Bob and Judy are busy that day, but they will meet up in one week when Paul passes through town again.
Bob and Judy are upset at the awkward situation and ask Bon to leave.