I saw them yiffing!

[The Final Kira]

I saw you yiffing your clone.  

[Deaths kitsune]

i saw you yiffing my split personality
(you'll see him ever once and a while on gaia.)  

[AnaFox 2012]

I saw you yiffing in the pool making it dirty  

[Deaths kitsune]

i saw you yiffingin the shower  

[AnaFox 2012]

I saw you yiffing a 5 year old  

[Deaths kitsune]

(that might be taking it too far)
I saw you yiffing everyone's childhood  

[WolfxLycan]

I saw you yiffing the dead squirrel dangling from the powerline 0.o  

[AnaFox 2012]

I saw you yiffing a pole  

[Deaths kitsune]

i saw you yiffing a dancer.
(i win : P)  

[Venom Schatten]

I saw you yiffing your red wolf gonk  

[Ask Jappleack]

i saw you yiffing the whole spongbob cast, including the characters that are there for one episode XD  

[AnaFox 2012]

i saw you yiffing on the gammy award ceremony.  

[Deaths kitsune]

i saw you yiffing a speaker  

[Kashinami-chan]

I saw you yiffing frogger.  

[Deaths kitsune]

i saw you yiffing a bandaid