[99 44/100% pure]

You all have given such good advice lately, on such issues as taking care of neighborhood bullies, what to do when your friend can't face up to the fact that he's gay, etc, so I've got another one for you:

A friend of mine (not lurking around this site, so feel free to be blunt) has a live-in boyfriend and her two daughters (ages 10 and 12) at home. The boyfriend has recently changed jobs and now works at night. She is concerned because the BF is now home with the girls during the day (kids are off from school for the summer; she works daytime hours), and, she recently discovered, apparently spends at least some chunk of that time looking at porn on the internet.

Now, she's no prude -- porn's OK, in moderation, and there has been no reason to suspect that anything untoward is going on, or even might go on, but something about the current situation gives her the willies. As far as I know, they've not yet even discussed this, but she's wondering if:
a) her gut feelings of discomfort are way out of line;
b) she has any business telling him what he can and cannot look at, on the internet or otherwise;
c) she's a fool for not speaking up immediately;
d) this guy's a perv and has got to go.

Any advice?