A question about helping a friend

[manasecret]

I have two good friends. One's name let's say is Jess, while the other let's say is Brad. They've been seriously dating for the past two semesters (about nine months), and because I knew Jess before I knew Brad, and only met Brad through Jess when they started dating, Jess is therefore the better friend. However, all three of us hang out all the time and we've all become good friends, all the while I still talk to Jess more often.

It's the last year of Uni for all three of us. So they're working through their "what do we do now, do we try to stay together even though we're moving to different places, or do we just make it easier on each other and split up?" stage. For the past week or so Brad has been leaning heavily towards the "let's just end it now" argument, while Jess wants to at least try and make it work and see if they can stick together. Like I said, I'm much better friends with Jess and she's been needing some advice/someone to talk to stuff, and I've listened as best as I can and say what I can. It's been hitting Jess hard, since she doesn't understand why Brad wants to break it off without even trying to keep things together blah blah blah blah...

Okay, whatever, that's their deal and I don't need advice on that.

My question is, after listening to the heartache of Jess for the past week I just found out from Brad's roommate that Brad is actually cheating on her. Now, what do I do?

Do I try to slyly insinuate it? (I tried, didn't quite work.)

Do I tell her outright?

Do I confront Brad and tell him if he doesn't tell her I'm going to tell her?

Do I do nothing?

I've never been in this situation, but my gut tells me that, even if Jess were to get mad at me for whatever reason, the truth is always better, even if it hurts.