Known by many names, morning breath describes the horrible taste and smell your mouth has in the morning when you wake up, even if you've brushed your teeth and all the night before.
It's especially bad when coupled with a hangover.
Morning breath is the bane of all those who fall asleep together and wake up wanting to kiss (but hopefully don't for both of their sakes!).
At the very least pull a dental denial before kissing anyone in the morning!
She was disgusted when her boyfriend gave her a kiss as soon as he woke up and promptly told him that morning breath can kill small woodland creatures.