Mutual Friends Invited Me to a Guy's House. We Don't Really Talk Though. Do I Go Anyway, or Pass On the Invite?? Please Help, it's Tomorrow!! D:

I’m female, 22 in university, and I have social anxiety so it’s difficult to meet ppl and make friends. I’m in a small writing class and there’s a guy “Nick,” who I’ve noticed has been stealing glances/staring every now and then since the class started. A few weeks ago the class had to openly critique each other's short stories. When it was my turn, he raised his hand and complimented my work, saying that it was his favorite. Shortly thereafter I was talking to girl in our class (Sarah) and she told me that Nick said I “seemed really interesting, and he wanted to get to know me but I’m so quiet.”

For the past 4 weeks she's invited me to lunch with her group, which includes Nick. I've been twice, the first time I went he was there. He asked me things like what year I was in, my major, why I sit so far away from them in class, etc. I was nervous/caught off guard so my answers were short, and I stuttered badly with the last question. -_- Last week he wasn't at lunch, but Sarah, her bf and her other friend Jess were. We bonded and we exchanged numbers. Before I went home, Jess asked if I was going to join them on Sunday at Nick’s house to study for the exam. I said I’d feel awkward since we don’t really talk, but they were like “oh, no, it’s fine.” And then Sarah was like “he likes you.” :o I’m really not getting that vibe, lol. Maybe at first he wanted to be friends, but I dunno anymore. I think I just came off too shy, weird, and possibly stupid to him, since he’s made no effort to talk to me after that first time.

Sarah msged us all on facebook two days ago and started an online study group. Sarah and I contributed the most to the group. Nick msged us later to thank us for all the info and said he’d repay everyone with food at his house tomorrow. I don’t have his address, and I’m not comfortable asking since I still don’t feel like he officially invited me. I'm not sure if I should even bother going. It's his house, he never invited me and we've talked only once. But I don't know how this will impact my new friends. :( What would you do?