Should I ask again?

Ask once more, but not again. Then you'll look desperate, and women don't respect that.

I would wait a little bit if I were you.
You've made it obvious to her that you want to hang out, so now its up to her to make it obvious that she wants to hang out with you.
Its understandable that she forgot to get back to you. I believe that. But give her some time to think "hm. I really wouldn't mind hanging out with _______" know what I mean?
I know its hard to not ask her again right away. but give her some time. wait a couple more days or a week or something so it doesn't seem like your desperate. Like, personally I wouldn't mind if a guy kept asking me to do stuff with him; it would actually show that he cared and I wouldn't think of it as him being desperate, I would think of it as wow this guy likes me alot. but it depends on how she takes it.
So my advice: wait a little longer and then ask again. If she keeps turning you down because she's too busy (does it a few more times) I would give up because no matter how busy a girl is, she'll make time for a guy if she likes him enough.

I posted this the other day, but it was erroneously removed (for being a duplicate post, which it is not), so here it is again:


You need some tough love my friend. To put it bluntly: you're coming off like a needy supplicating wuss. Sack up and take the lead. I strongly suggest you give this a read:

"Cute Girl says:

I like nice guys; that's not the problem. I just met you and you are telling me how much you want to date me and asking for my phone number and I am probably not ready. You just come on too strong and too fast. You come across as desperate by telling me how special and beautiful I am, you tell me you LOVE ME SOOO MUCH, that you will always treat me right, how I'm the one you have always been looking for, how good you will treat me, and all that rubbish.

I'd rather a guy try to get into my pants. If only you would just give me a little time and space, but NOOO you have to LOVE me. So I choose the good looking bad boys. You can slap their face and they just smile. At least with the bad boys, if and when I decide I'm not interested, they don't give a hoot. I'm not going to hurt them.

Like most girls, I’m a compassionate person; I don’t wish to wish to hurt anyone. But if I decide I don’t want to date you anymore, you are going to be SOOO hurt. I can see it in your face, your expression, and body language. You try to get me back, you mope and complain, you point out all the things you have given me, and tell me how badly I’m treating you, or maybe even talk about suicide.

I don't want to deal with any of that crap, let alone most of it. If you give me the slightest indication you are going to be that way, that's it; I'm not having anything to do with. If you act like that, I don’t think you are a nice guys at all, I think you are a selfish clingy bastard posing as nice guys just to get me, the girl. You don’t care about me; if you did, you would be happy for me when I wanted to go because that would be what I wanted. But, no you are selfish and want me to stay and love you even though that is not what I want.

When you want to go bowling with one of your guy friends and he tells you he has a date and can’t go, you would like for him to go but you don’t get miffed or get your feelings hurt. It's hard for me to tell you what you don't want to hear when I know you are so enthused and you will be SOOO disappointed. If you would give me the same considerations you give your guy friends and not be offended and get your feeling hurt, I might go out with you."

dude if you still like her, give her some space, but if you wanna be friends then just stay on her and little by little you'll find out if she's being a fake friend or real friend.