We live rurally in a farmhouse and have a long term friend who lives in the city. He comes to stay with us several times a year and in the past he has stayed in the house while were away.
Last time we found out that his daughter had come to stay for a few days, that's fine as we know her but we only found out because DD1 discovered a sock in her bed that wasn't hers. On that occasion he also invited his sister, although I think that was just for the day. We also remember one other occasion from the time before that he had a previous girlfriend stay without us knowing beforehand.
We are going on holiday soon but this time DS1 (19) is staying behind, he will be at work. Despite this we asked if our friend would like to come as he has a thesis to write and we thought the quiet would help. DS is OK with this as he knows him well.
However, the friend asked if he could bring his new girlfriend. He hadn't mentioned this on the phone to DH but 'confirmed' her visit in an e-mail yesterday. Now, we have never met this girlfriend who he has only known a couple of months, and don't think it would be fair on DS to have someone in the house that he doesn't know, especially as he may be at work when she arrives, so we said no. The friend has taken a big huff with us as he 'cannot be away from her for a whole week' and is surprised by our reaction.
Our reaction is simply that no, not on this occasion but she is welcome to come and visit when we get home. We are more bothered that he told her she could come without even asking us first but he thinks we are the ones being unreasonable.