Not autobiographical, eh...?
Anyway, nice and easily readable, but I wonder if Jenn's scenes go on a bit too long -- I felt it was beginning to border on the self-indulgent, especially as it's so not autobiographical... She's bored, she's a wannabe writer in a dead-end job (literally, it seems...) and she has a crush on a film star. Do we need to know more than that at this stage? Can the slovenly habits and the rest of it wait for later in the book?
There's an awful lot of telling in there, as well -- the para about Ben Barnes'... ooops... Ambrose's perfections in particular seems like a ginormous info-dump. I think it might read better if you took out most of that and again fed it through later on.
As for Ambrose, is the bit about the bubble bath going to be super-relevant, because the titanium oxide causes him to swap bodies with someone else, or come back with superpowers? If so, fine. If not, to me it's a distraction so again I'd wonder about its inclusion, especially in the opening lines. And is that a real ingredients list? Because it doesn't sound it to me -- shea butter in a body lotion, yes, but in a bubble bath? And why bother with organic if the other stuff isn't? And if Mercer is a gofer, wouldn't he/she have run the bath? In which case it would be a hanging offence to leave the empty bottle there.
Other nit-picking -- a posh hotel with carpet on the bathroom floor??? And aren't there very stringent rules about electric bulbs in bathrooms, to avoid all possible chance of electric shocks?