Oh, i thought you said that you had a girlfriend
anyway... in what way doesn't she consider you the same as liz?
from my narrow personal experience, I've found that my girl (space) friend (as in girls that are my friends) sees me in a way, and my girlfriend sees me in a different way... but still it all turned out wonderfull...
(half past 2 at night.. better go to sleep now).
hard to explain when you're tired.. but I think you understand..
Spend some more time with that chelsea, and "feel her mood", cause if she's all happy around you, and talkactive, and yeh, such things.. then there's a good chance that she might like you...
that movie thing could be coincidental... i mean... her friends maybe thought you were a weirdo.. and didn't want to spend the evening with you, and chelsea maybe didn't want to argue with her friends, and thereby sat with them, when she wanted to sit with you..
AND ALSO!
i think liz might've scared her away... you see... it'd feel really awkward sitting with someone you like, with another girl as well... think about it.
You find this one girl really attractive, and you go to the movies, and she sits, and spends time with, another guy, wouldn't that make you feel uneasy?
soo... try spending some time with her alone
EDIT:
well, you're probably right. After all, you know them and we don't.
anyway, I get what you're saying and I guess I can kind of picture it (in a loong time).
Yeah, well... You're the only one to know and decide what you want to do, and what feels best for you, and what you can picture or not..
But one final thing to say is: Don't feel any pressure about sex... if your friends has it, or someone talks a lot about it... screw them! the only thing that matters is yourself! (and the partner of course). (and i mean, in the future when the topic might be more topical).