I suspect he finally figured out that his sibling and his mom were out together and maybe even doing all of the things he so loved to do with you in the show ring, having seen things you packed. It may have taken this long for him to put two and two together and when he did, the situation was untenable! I believe he was jealous and who could blame him?
__________________  Jeanie and Tibbe One must do the best one can. You may get some marks for a very imperfect answer: you will certainly get none for leaving the question alone. C. S. Lewis |