text: is it possible not to know you have bad breath or body odor? had a friend once who everyone could smell to have body odor but i don't think she knew... so just wanted to know this.  and while kissing someone, can you tell if you or the person you're kissing has bad breath? people who smell bad, or have bad breath often times don't realize it. sometimes it becomes apparent from the reactions of other people, sometimes it doesn't. if you kiss someone with bad breath, it usually hits you right in the face (no pun intended!).