I'll call out the elephant in the room.
you're being fucking weird. Why? Because you are doing extreme dirty talk over facebook chat. Allow me to give you honest balls-to-the-wall checklist for facebook chat.
1. You
do not go sexual over fb or other IM, unless you have already got sexual in person
2. Minimise your talking over social networks, just use them to get the girl to meet up with you. They are there to get you and her together in person. They are not supposed to be the primary mode of communication.
3. You are taking this way to sexual even if you were saying this in person. And over IM it's past the point of being weird.
I think it might be easiest if I broke this down line by line. My comments are in bold.
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Me: Arn't you on the volleyball team?
- Normal social question. Fine.
Her: Yeah
Me: Your boobs slap you in the face when you jump don't they. Lmfao
- Weird question. It's not complimentary at all to a girl - it's some weird sort of embarrassing imagery?? why is she going to like that? And your going sexual over IM, which rarely goes well even if done right. Best just not to go sexual at all over fb/IM. Just dont say this sort of thing. It's not complimentary, so why would she like it?
Her: Lmfao O.o
- Yeah, the "O.o" translates as "what the fuck??"
Me: Haha that would be funny af.
- You continue on the thread. Your adding nothing in terms of value. She's not going to give you much back from this...
Her: How ? Aha
- She gives you almost nothing back. Right now she's only still talking from a curiosity as to where on earth this very weird topic of conversation is going.
Me: You just never see the happen haha
- you contine to add nothing. you are looking for her to jump onto the topic and say something, but she isn't. And I don't blame her, I would be saying anything either.
Her: And you do? Lmao
- again she gives you nothing. She is doing no investment, and there is every sign she is just talking back out of a morbid curiosity as to why anyone would be talking about such a weird, socially uncalibrated topic of conversation. Instead she makes a joke that implies you watch weird things. Not a great position to be in. read between the lines mate.
Me: Hell yea. Nah jk Lol but i know yours probably bounce like hell
- NOOOOOOOOOOOOO!!! DO. NOT. GET. SEXUAL. OVER. IM. OR. FACEBOOK CHAT.
Her: Lmfao ._.
- The "._." translates as "you obviously thought that was a compliment, but it really wasn't"
Me: Haha i was right (;
Her: Lol idk.
- She gives you nothing
Me: I'm probably gonna end up having a dream of us banging tonight -__- lmao. - DEAR GOD DO NOT SAY THIS TO A GIRL UNLESS IT IS REALLY, REALLY ON. Do not get sexual over text/IM/etc. You are constantly pushing for sex in an awkward and unsmooth way, with a girl who isn't attrated to you, who has a boyfriend. It's just not on, and pushing it in this way
(She fell asleep)
Her: Lol i fell asleep. Thats why i didn't answer.
- She might, or she might not. In my opinion, is it just as likely that she found the "dream of banging you" thing too intense for even her, and stopped reply to stop the awkward advances.
Me: Lol i figured haha and i had a dream about banging but it wasn't you -
Do I need to say it? Don't do this.
Her: oh darnn .
(I was really surprised by that considering she has a boyfriend but it gets bad)
- and you were wrong. The full stop at the end of it implies sarcasm. she is actually telling you that she ISN'T dissapointed at all. She is telling you to stop this thread of conversation!!
Me: Hey
Her:Hey
Me: If you didnt have a boyfriend would you go with me to the movies & makeout etc?
- Never say this to a girl again. This is essentially asking "do you find me attractive", or "would you date me". This is weak, needy, and insecure in person, and is ten times as bad over IM/text/fb chat. Don't do it.
Her: Hm.. idk
- translation: "No, but I don't want to hurt your feelings by just saying no outright"
Me: Maybe we'll see one day.
Her: Maybbbeee.
Me: (;
Her:Lol
Me: You ever had a dream of us banging?
- Fucking hell mate. Just fucking stop!
Her:Lol no
- You've pushed her so far she has started giving you outright no's.
Me: Its fun lmao. Want me to tell you if i have one tonight?
Her:Lol sure
(I woke up at about 5:00 am and sent this)
- In general, don't send girls messages this early. It looks needy and overinvested, and hence is not attractive.
Me: I had some good thoughts before i went to sleep but no dream about it. my cock is so hard for you right now tho.
Her: Wow. Aha - Translation: I can't believe anyone would actually say that. And I don't mean that in a good confident way. I mean that in a bad way.
Me:Haha (;
Her:You're weird. Lmfao (I hate being called this cause i have by so many girls so i just said to myself "Fuck it ill just admit to what i'm considered by most girls")
Me: Hell yea i am. You didn't know? Lol
- This is the first time you've actually done something right. This is good objection handling. Don't fight it, agree and don't care. Good.
Her: Lol oh, i knew.
Me: Makes me unpredictable though. I am who i am. Lmao
- again, good. But don't do any more than this. Anymore is overkill and will kill the good stuff your last 2 responses did. you want to change the topic to something other than you now.
Her: Lol Yuuuup.
Me: I can't count on one hand all the hot girls ive dated so whatever it is they dig it idgaf haha
- And here you loose it again. This is classic mistake for guys who have read lots about meeting girls. You try to hit the preselection thing, but you don't realize that everything else in your conversation so far has give then deafeningly loud message that you don't get hot girls. So this just comes across as false, and so she is unlikely to give you much, if anything back at all...
Her:Lol
- She gives you nothing back at all.
(Later that day where i fuck up)
Me: Hey
Her:Hey
Me: You chilin?
Her:Yepp lol
Me: Layin down? (;
Her: Yeah .
Me: Haha sounds relaxing i remember that night you and grace called me watching the grudge.
Her: Haha i'm right next to her.
Me: Tell her i said she has crazy fat jokes. Lmao.
- not complimentary, so why would she love that? Here something complimentary to grace would have been gold - e.g. "tell grace that she had beautiful hair when I ran into her yesterday. Ringlets really suit her".
Her: She said oh. Aha
- translation: "err...thanks...I think....?"
Me:Lol and tell Sidney(Sidney is her) i want to know if she's a good kisser.
- DO NOT GO SEXUAL OVER TEXT/IM, but equally important, do not start escillating infront of a friend. And especially not over IM. Even if you'de had the most awesome IM conversation with Sydney over the past few days, saying this infront of Grace would have lead to Grace interigating Sydney about you, because that's what girls do.
Her:.___.
- Translation: "Awkward....."
Me:Haha just askin.
Her:Ok. Lol
Me: I bet you kiss atleast average.
- This is a big fucking insult to a girl. Why would you say it? But talking about kissing over IM/fb chat is not going to go well anyway.
Her: Ok?
So I have been very honest and pretty harsh at times in this breakdown. But it wasn't personal. You're probably an awesome guy, with a cool life and a good heart. But you're missing the important social queues which is the reason you are coming across weird. Sex and sexuality can only really be done in person. Sure, once you are in a relationship you can do dirty texting and IM messaging, but not to a girl who you havn't slept with. Seriously, don't take the above critisisms as personal. Instead learn from them. And next time you post something like this, feel free to drop me a pm so I don't miss it, and I'll do whatever I can to help you out again. 
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