Dead Souls - J Lincoln Fenn - Bog

"When Fiona Quinn is approached in a bar by a man who calls himself Scratch and claims he's the devil, she figures it's just some kind of post-modern ironic pickup line. But since he offers to pick up the tab, what the hell. A few drinks in, Scratch offers something much stranger--a wish in exchange for her immortal soul. Fiona has been wondering if her boyfriend is having an affair. What if she could become invisible, see what he's really up to? It can be done, but for a price--in addition to her soul, Fiona must perform a special favor for Scratch whenever the time comes"--