Fart Song

I'm not insane when I'm talking to you, babe.
I want to set the place on fire
If you see me smoking then it's probably me, now.
I'm burning up with desire
I'm not in love when I'm talking to you, babe.
I'm just with people standing in line
If you see me smoking then it's probably me, now.
(the whole last line is a mystery to me)