It's very normal for a yorkie to go pee alot in one day. their bladder can hold about the same amount as an 8 oz glass. so if they have been drinking alot theyre def going to go alot! my girl is very active so she gulps down water everytime she can and when they drink, they usually have to go about an hour later. so i would say she goes about 10 times a day! but in very small amounts. i think ur boy is just fine