To be on the safe side all around, you should get another Boston. Two Bostons playing together is the best sight in the world anyway. They are a muscular and stong dog, and may not be suited for a Yorkie. I had a Boston girl and yes, she was a breeze to house train and never had "accidents" in the home. I have three Yorkies now and was totally devoted to house training the first two for a year and now I trust them completely. The youngest one is 7 months and still in training and I would not trust her to have run of the house just yet. Maybe when she's a year old or more.
