Question on Flashback

Just caught the flashback episode from Season 3. This seems a bit odd to me but why when Janice asked "who has slept with who?" Ross responded with "none of us." Did he forget the hot piece of ass aka Rachel sitting on his lap. Seemed like an idiotic piece of writing to me.

Hellooooo!!! After getting drunk in Vegas, Omarichu doodled cat whiskers on his/her face and miaowed this little lot at a statue...

I took that one as meaning 'Who has slept with who, BESIDES Ross and Rachel because that one's obvious?'. Hmmmmph.

Omarichu wrote...

WHAT ??? I'm shocked to my very core ! =<> He didn't reply "It's 'who slept with *whom* ?' !" Wow! that is soooo out of character of him to not say that !

Adeline.