What Is The White Discharge After Having Intercourse?

i just had sex with my wife and she goes uses bathroom in the middle of have sex. I was I was waiting for do her business. Then when she was done, I stick my penis in her vagina and I finished having with sex her. And just now she put on underwear. And I saw some white stuff., it seemed like she was peeing seimen, is that possible ( I have no clue what that is…. What is it? )