Haha, that's funny
You say 'haha, that's funny' when you're trying to be cool and you say '69' and '420' like they mean something important.
'Haha, that's funny' when I said '69' and my friend asked what that meant.
'Haha, that's funny' when I said '420' and my friend had no idea what I was talking about.
'Haha, that's funny' when I said both '69' and '420' and nobody got it.