Lyric discussion by vintage_me 

Cover art for Don't Sleep lyrics by My American Heart

so as for actually explaining the song MEANiNG as this site is meant for....

we've got a liar on our hands. a girl who lied and he heard from someone the truth. not from her. "Dont sleep, dont sleep so sound tonight" means dont be so okay with lying to me, you should be hurting too. And "cause the sound still sleeps the same with you away" means there are still no words coming from the girl. Silence remains. She leaves. He's trying to find closure in her absense.