<human>: Could you distill the essence of the text into 1-3 sentences?

So, I've been seeing this girl for about 2 months, it started as just a hook up and have sex arrangement but I'm starting to see something more in it. But there's an issue I'm having trouble shaking.

When we initially hooked up she had a boyfriend and was at the tail end of the relationship. I had that information and it didn't really hit me until the next day how much of a terrible person I'd been (or was, or am). I am fully aware of how much irony is present in the following paragraphs.

I've known this girl quite a while and in addition know she has cheated on a past boyfriends. I'm really starting to like her and I'm yet to have a conversation with her about how I feel in this regard. I'm concerned it will drive her away and kill any trust that we might have. But I'm just terrified of keeping the judgment to myself and having it manifest in ways that will kill the relationship anyway.

So do I try and ignore it or do I face up and talk with her about it? Or is it something best avoided? Has anybody had a similar experience and can offer some advice? I'd really appreciate any thoughts on the situation as I'm far too close to it to think rationally.
<bot>: I'm seeing a girl who I know has been unfaithful in previous relationships and it concerns me going into a relationship with her. Should I be? Please help.