My hubby and I invited a couple, good friends of ours, to visit our holiday apartment (I am Greek) and stay with us in Greece next summer since they had never been to this particular island, and they booked flights to stay with us for a week. My friend then told me she was speaking to a friend of hers (that we never met) and that they (her friend and husband) will probably join us in the summer (although staying in a hotel). I really don't fancy spending time with strangers when we specifically invited only our friends to spend time with us... am I being unreasonable??