i also have a teeny little boy [2lbs @ 7 months] who thinks he is a great dane. I know its so easy to be over proctective, i am sooo guilty of that. i do get nervous about him gettin stepped on, or other dogs being too rough, but for the most part the other dogs can somehow sense that they need to be gentle. siri's cousin is a german shepard who is super sweet with him. like Nobella said, i only let him play with dogs i know. i think preston will prob grow a little more, and you will get more comfortable with his size also as time goes by, and so will your other dogs. :]
i let siri sleep with me allllll the time, i had originally not wanted to allow it, but i couldnt deal with those cute little wimpers!! i never squish him, and he also lets me know when he wants to get down and all that. best of luck!!
__________________ To eRr is HuMan, To FoRgiVe, CaNiNe  Jackie & Sirius |