The girl I had oneitis on has a birthday next Saturday. She hasn't announced any party yet nor invited me but she probably will and I'm wondering how to respond if such thing happen.

Some more info about us: both 19, we're in same college group, managed to fuck her couple times despite having oneitis on her. Now mostly thanks to TRP I realized she's a slut and tried to disconnect emotionally from her. I broke contact with her a month ago for like 2-3 weeks and went into monk mode which helped me a lot. Before breaking contact I went super beta infront of her and that's why I broke contact, to get my shit straight again. And well, here I am, stronger than ever, even less feelings to her. We flirt back again in classes, she comes by for coffee to my place, it would be nice to fuck her again, so how do I play the situation next week that might occur?

Now, she probably won't make the event at any other place than her flat because she's broke (slutty clothes and cigs ain't cheap yo). So what option should I choose?

1) I go there, have no fun because I don't have same topics with probably invited people. But be there for her, leave early because I don't like not sleeping enough next day and hangover. (might test her if she stops me from leaving and tells me I can sleep with her)

2) I don't go there, do something productive, if she asks why I didn't come I tell her I was set up with someone else (even if I'm not), might make her jealous if I play my cards right

3) I don't go there, if she asks why I didn't come I tell her I don't like these kind of parties or I just tell I didn't feel like going there.

Additional question: should I wish her happy birthday through sms or w/e if I don't go there or just ignore this shit

Additional question 2: if I refuse going there maybe I should tell her something along lines: "you can come to me later individually for your birthday present if you want"?

Now. I feel like choosing option 2) because I'd like to check if she's gonna be jealous. There was a high upvoted post about how to know you're dating a slut, and well, she had most of the points in there, one of them was that they're really jealous. So I'd really like to check that.

Thoughts?