Why does my call me a pussy and spanks me?

I assume you left out the word "wife". It's because you are a closet submissive who needs to be used and to please others sexually. When she calls you Pussy it feels so right and good and natural, like you are finally recognized for who you really are. I'd say she either wants to go all dominant on you or is seeking to provoke you to fuck her brains out, or much more likely wants to cuckold you so she can get some real man-cock while you watch or participate. Either way you should ask her. You're in for a good time.