[OwnedByJezebel]

I haven't been around many Cavaliers, but the ones I have been around were friendly and didn't tend to try and dominate. Since terriers can tend to want to be alpha, a Cavalier could be a good fit.

As far as gender goes, since you are getting a male Yorkie, I would get a female Cavalier. I think they will get along easier if they are opposite gender-wise. Just get your Yorkie first, and neuter him, then get the Cav. No need to chance getting those hormones going (easier if he doesn't ever start marking in your home) or even an accidental pregnancy.