When ever you use someone's ass to start a fire
That bitch Sandra is a perfect fire starter
Noun. adj, 1. The thought that when a womans breasts are so big that when rapidly rubbed together and with the help of spontaneous combustion they could ignite into flames.
Small titties could not be fire starters because they couldn't possible produce enough heat from the friction to ignite by themselves.
"Wouldja look at them fire starters on that bitch! I could sop them up with some 'biscuts n gravy'."