Used when the woman during anal secretes a semi/fluid excrement while the male is humping her, the fluid starts bubbling as a result.
"Damn bro, I fucked her and I didn't even realize I gave her fluffy germs"
The phrase used to define a lady's anus when doing anal intercourse when she shat liquid poo while the man kept thrusting into it, thus forming Fluffy Germs
I didn't realize I gave her the Fluffy Germs