I waited a long time (12 years) before adding a second Yorkie. I was always concerned about my boy not liking the addition. But I finally decided to take the plunge after falling in love with my Gia upon laying eyes on her. So I got her at 12 weeks of age earlier this year and after a long adjusting period, they truly have become "siblings". They rarely fight. They love cuddling together and play all day! She learns a lot from the older one and he hasn't played so much in years! It's double the cost for food, Vet care, shampoos, clothes etc. The initial cost was considerable as a new puppy needs all new stuff of course! It's also double the work. To comb/bathe/brush teeth/clip nails/dry off and comb again takes me around two hours now. Walking two at the same time took some getting used to. Traveling with two instead of one is more inconvenient now and finding a babysitter willing to take on 2 is also a challenge. But I wouldn't trade it for the world and I'm thinking about a third as well! Just like Wylie's mom said, the whole training period all over again was hard work but also very fun! Maybe you can offer to babysit somebody's Yorkie for a few days and see for yourself if you like it!