I actually went ahead and talked to her..
Even if I fucked everything up I wanted to explain myself and just make sure she wouldn't be forever pissed at me, since she's still friends of friends and we hang out often together.
Here's how the conversation went :
The wording is not exact, english is not my mother tongue.
Me : Are you still mad, silly

?
Her : No but I'm dying it's so hot lol
Me : It's better to be hot I think
Her : I'm not sure about that lol! what are you up to?
Me : was Playing guitar, just got great news, I was hired at that rock climbing gym I've told you about
Her : That's great!!
Me : So what was with the funky attitude the other night huh? I think out of us two, I should've been the one who was mad and I wasn't really haha.
Her : I don't know, I was tired and didn't like the way you reacted when I told you for the dinner.
Me : Oh really? I thought I reacted pretty neutrally to be frank

I was just looking forward to taking you to dinner really.
Her : I know
Me : I don't think I made you feel cheap or anything, I even brought you flowers

!! (Refering to the ugly stuff I gave her the same night )
Her : lol!
Me : what specifically didn't you like about the way I reacted
Her : well you said '' you must feel like having dinner with your friends better than go out with me''
Me : Well doesn't that make a bit of sense? Unless they were holding a gun to your head haha. It's just that the way things acted out It sent me the message that your interest for the dinner wasn't as high as mine.
Her : I didn't realise that on the spot, I realise it now, I'm sorry. Anyways, I wasn't mad for a long time
Me : Yeah and I don't think you could be mad at me for reacting like that.
Her : I know, and it would be fun to have diner soon. And I'm not going to choke, I promise.
Her : I gotta go I'm heading to town with my mom, talk to you soon xxxx
Me : Sure, have fun! xxxx
Her : Have a good night
Her : =)