Im really confused, does this girl like me? Please read I need help and advice!

Ive known this girl for 2 years now. Shes 18 and im 17. We've been great friends her brother is my bestfriend and we always hangout, i even stay at their house sometimes. Anyway this girl ive started to like as i got to know her more but shes been in a 2 year on-and-off relationship with this guy which is why i try not to make it obvious i like her. Last year i asked her out when they supposedly broke up, they were apparantly talking again when i asked her out, and she told me i wasnt her type. I knew it was a bad move on my part because i knew their break up wasnt serious but i really liked her and said what the heck. Btw she told me hes jealous of me because he think i like her (she told me) and i thought this was a good sign.
After that i started to think of her as a friend and respected the relationship she had even though they broke up a lot for stupid reasons. A lot of guys like her and i try not to be one of them, for a while i didnt get hurt seeing her with her bf or had no intention of liking her like that again but this month when i stayed over her house for break she acted more flirty i think. We've always teased each other like "b* you aint gone do s**" lol shes really silly and goofy which is what i like about her, she always calls me weird as well which i think is a sign she likes me. Anyway this time it was more physical than usual. After teasing each other she stood in front of me saying "do sum then!" So i grabbed her and started to tickle her and wrestled, haha it was pretty fun i have to admit, and this happened like 4 times. The 4th time she even gave me a wet willy and after that hit me in the head when she passed by where i was sitting, and would spray my face with her wet hands, to me this is obviously flirting but idk if she meant it that way ). After all that i realized i love her, and i hate myself for it, because i dont want to, not when shes been with someone for so long, i mean no one decides who to like right?
The next day we wanted to go out so when we went to her mom to ask for permission i had an idea but i didnt tell the girl. We came up to her mom and i said, "Liz we need to have a serious talk", i was being sarcastic and was about to bring up "The Talk" when suddenly the girl blurted out "Were getting married!" I didnt expect that and just said "what haha no" we all just laughed. And her mom said i looked shocked. This is what confused me the most, why would she say that?? Does she like me?? Im really confused because i like her and i dont know if i should confront her about it because im afraid ill just look desperate and like those other guys that like her, i dont want her to know if she doesnt feel the same.
Anyway, the next day was new years eve and we had a little party and her boyfriend came. I minded a little because lately hes been very confrontational as well. He would shadow box me and stuff, i like the guy but knowing he doesnt like me and doing that makes me want to punch him, he also said "you must wanna fight" i just play along and say "wassup then" but its nothing serious.
Anyway when we were in the living room her bf was in one sofa talking to his friend i was watching tv and his girlfriend sat next to me, then he said "theres more room here you know" idk why she did that though tbh because she never sits by me. But that night i was unusually quiet, seeing them together made me feel sad and alone because i love her and this time it was affecting me really bad seeing them together, and i hated myself for it because i let myself fall in love again. It was all i had going through my mind that night. We were playing a card game and she noticed this and said "her are you okay? It looks like you got scolded or something." I just said "haha im fine im just sleepy". After everyone left i decided to leave as well because i didnt want to see her. I went to my house and the next evening i thought about that night, and her, and for the first time in years i began to cry... It felt like all that suppressed emotion i was holding back and being the "i dont care" tough guy burst out. I felt horrible and depressed and asked God for help and i actually felt a little better after that.
I came here for advice because i have no idea what to to do. Does this girl like me? I wish i didnt love her but i do, i know i am because i could see her with her bf no big deal, which meant that i like to see her happy, but those few days of teasing each other and messing around made me feel more connected with her, i actually felt happy as well, and seeing her in another guys arms after that was killing me, and i hate myself for feeling so offended by it. Should i talk to her and ask her why she said we were getting married and if she likes me?? Should i just ignore all of it? Idk what to do because what if she does like me and is holding it back just like i am? Why was she so flirty this time? And whats with the marriage thing is she actually thinking of dating me in the future??Sorry i have so many questions but im really confused. Please help i really will appreciate you guys for posting! God bless.

When she told you that you weren't her type last year, you did good in accepting it and moving on. I can understand though that being a friend of her brother and staying over to their house sometimes, makes things difficult for you, especially if she flirts and wrestles with you. She shouldn't be doing this since she's been with her boyfriend for two years and doesn't see you as a potential boyfriend, so try not interpret it in any other way than her enjoying getting your attention for an ego boost.

She is probably unaware that she is leading you on a bit or maybe not, but my advice for you would be to not to flirt with her anymore because while she's simply having fun, you're having a really hard time. She's 18, you're 17, she probably fantasizes about boys of her age or a bit older, not that the 1 year age gap really makes a difference, but teenage girls tend to think like that. She's been on and off with her boyfriend for two years, so she's unavailable and you shouldn't invest any feelings but look for a girl who doesn't have a boyfriend and could be interested in being your girlfriend. Also she seems to be pretty open and daring, so have no doubts that if she had really felt something for you all this time, she wouldn't have had any problems letting you know this. Just treat her as your best friend's sister, because that's all she is for you and look for a girl who you could date and have fun with.

Being at your guy's age a person can change their mind for sure. This is what you do.....stop getting too close to her, don't give her anymore of that attention. Don't worry this will not push her away or turn her off, in fact it will do the opposite. Act distant, and aloof. Have a cold, kool demeanor, like you just don't care, and that you are the shit. Talk about other girls to her brother and make sure she can over hear your conversation....this will make her so jealous. The more undesirable you make yourself out to be, the more desirable you will become to her. You might not have her in your arms instantly, this may take months.....maybe a year or so. Just don't show her your feelings for her period....that will kill it for you. Best of luck and keep me posted on your progress.