in S5 the very 1st episode, do you know what Chandler meant when he and Monica was trying to get away from Ross to have sex and he told Ross it's a very large plane? I never could understand that.

I always figured he was just saying that cos his mind was somewhere completely else (aka in the gutter) and “something” else was large at that very moment so that was the only word that came to his mind?

But I could be wrong so if anyone else knows better…?