I have had my little guy (5 yrs old, neutered) since Sunday. He was doing so good...but this evening a disturbing behavior has developed. I have "my" chair that I sit on in the evenings, and little guy likes to sit right next to me. So this evening, my daughter & her dh, and 2 kids were visiting. One of the kids walked up to me while we (me and little guy) were sitting on the chair - and he growls and barks at the kids!

The kids weren't touching or even reaching for him...it's like he was protecting me or just behing aggressive. He did this 4 or 5 times this evening. I made him get down onto the floor, and after the second time did not let him back up on the furniture at all. When they were leaving, my s.i.l. reached over and touched my arm (I was holding little guy) and he barked/growled at my s.i.l!!! I am obviously concerned that he may bite or injure one of my grandchildren. They are here visiting maybe 1 evening a week.
Come to think of it, he did this once on Sunday (first day here) to my other s.i.l. - again, I was sitting in this chair and he was sitting with me. And he did it last night to my dh; dh was being goofy kind of moon dancing and he stopped right in front of me...little guy growled and barked at him! Both of these times, little guy was sitting right beside me and the person was right in front of my chair. Odd...
Have any of you ran into similar situations with aggressive behavior towards people? If so, how did you handle it? It makes me sad because he was doing so good! My daughter said to put him on the floor quickly and tell him NO, which I did - but it didn't seem to help. Acutally, after they left I went to take him off the chair because he had climbed up there, and he did the same thing to me when I reached for him...he barked/growled.
Any other advice? Thanks...