Spee's got a Sit'uashin

[Spee]

I broke up with my girlfriend at around the beginning of summer. Havnt seen her since, aside from fluke crossings at large areas/biking.

Recently went to a party with a group of friend she introduced me to, and is still a part of. Only, this time, she came with German Foreign Exchange student in tow. Cute, and speaks English well, despite having a heavy accent, which is to be expected.

Now, normally, I'd attempt to pursue a relationship with her, and she seems interested in me, but therein lies the problem: She lives with my ex. Considering I have made great pains to get back on "neutral" terms with her, Im at a loss as to how to proceed.

1: Go for it, possibly alienate Ex, who, with her close proximity, becomes a superbitch and tries to get her disinterested in me
2: Dont do anything, and shrug it off.

Opinions plz.