One question.

Is being sexually open with a girl the same as letting a girl know that you like her?

It really depends. You haven't given out much info of the relationship to really say but you should try to figure her out, keep your cool, and take her on a date (DYD style) so you can further establish a relationship and build comfort...unless you just want to bang her.

Vague answer to a vague question

I'm just looking for general answers to every case. i want to form a list of actions that accommodate situations. Perhaps at what stage should you do what etc.

At my stage we are quite comfortable around each other. i kino quite a bit, as i would like to think. we text and occasionally she calls me baby. but she doesn't like people teasing us. today when i told her i was disappointed in her not finding the courage to kiss me she told me "i would never sorry " - i don't know what this means.
that day she flipped out on me and told me how she lied to me about cutting her hair short (she didn't cut it) and how i didn't notice it.
Today's my birthday and i got excited over someone else's present and didn't get excited over *going to receive hers*. Her whole tone and mood of the conversation shifted. - would a girl who does not like you do this?

I'm not sure what i should do now. I am looking for a LTR with her.

First of all if today is your birthday, you should focus the day all on you and not even care about what anyone else does. If she tries to make a fight out of nothing today, dont give her any emotional respone, dont let her affect u in any way. Do the things that initially attracted her and be congruent.

It sounds to me like she got issues and you will probably face more shit tests with her lol

What I would do if I were you is DHV myself and make sure she knows how lucky she is to be with me and that I could get other girls if I wanted to. Be confident and calm all the way like her BS cant affect u. (If its hard, dont give up cause u can do it when u push yourself).

If you guys are gonna have a party then you should make a good impression at the beginning, maybe make a cute comment like "hey there's my cute little sidekick" (or something like that) and then talk to other girls later while kinda forgetting about her until she comes to you.

You should also try to be cocky & funny with her imo cause she sounds like a stuck up btich from what I'm hearing...Be more of a leader and take control in the relationship whenever you see the opportunity otherwise she will work her way to gain power and control.

Also maybe work on some push-pull routines to spice things up. Hope that helps, maybe others can give you better advice.

Happy Birthday btw and remember the focus is all on you today so you should have all the power.