I saw them yiffing!

[Kashinami-chan]

I enjoyed yiffing your boyfriend.

I saw you yiffing a swan.  

[Ask Jappleack]

i saw yu yiffing your triceratops in your avi, while eating a bagel with strawberry creamcheese  

[Kashinami-chan]

I saw you yiffing a dung beetle for your personal pleasure.  

[Gibistar]

I saw you yiffing Bill O'Riley  

[Ask Jappleack]

i saw you yiffing all the capital letters in the movie grease  

[cajunantichrist]

I saw you yiffing cheteq! surprised  

[Zi the Huskyfox]

I saw you yiffing my wolf doll crying  

[Gibistar]

I saw you yiffing a Chocolate Chip Cookie that looked like boobs! eek  

[AnaFox 2012]

I saw you yiffing a hot dog because you wanted d**k  

[Kashinami-chan]

I saw you yiffing a that cat around the corner.  

[Venom Schatten]

I saw you yiffing a lion on the zoo. Now he wants to scratch you.  

[raccoon menace]

I saw you yiffing in the van outside. I don't know who or what, but I heard lots of howling. o.o;
(Lol, page 69)  

[gamerguy121]

I saw you yiffing my Nintendogs!