Search Results: how long to wait before asking out

Short story: I feel like we both like each other but she mentioned she had a boyfriend.
Long story:I have a class this semester with this one girl that I like very much. She usually sits close or next to me each class and we talk most of the time if she sits close. Whenever she sits away from me (no assigned seats in the class) I swear I catch her peaking at me but I can't be sure unless I want to stare at her back. Whenever she sits by me we always end up talking after class. I know she wants to talk to me because she always gets up out of her seat before me and she'll be standing in front of my desk waiting for me while still talking. I mention this because if you're having a conversation with someone you don't like and class ends you get up and leave because fuck that dude you need to get to your next course, but no she waits for me. When we start walking to her next class it seems like her talking gets a little stuttery and her talking outside of class is so much more engaging than when we're in class. Like if you heard our conversations while walking to her next class you'd be thinking "these guys are so fucking corny". Our conversation, to me, really sounded like one of those awkward conversations that you have with someone you like and you try really hard not to fuck up. She even has corny goodbyes. I can't remember the goodbyes we've traded but I just know they've been corny, very corny. I'd be asking her out ASAP if I could be here's where my problem arises. Right after a class a couple weeks ago she very subtly inserted into the conversation that she had a boyfriend. She subtly added him to a conversation after class too but hasn't mentioned him again. The thing is that from everything I know about her I'm pretty sure she doesn't even have a boyfriend. Here's my question. Why is it that I think we share a similar connection but she said she had a boyfriend? Could there be a chance she likes me? Also if she doesn't have a boyfriend why would she lie?

How long is it acceptable to wait before asking a girl to meet up after she splits with her boyfriend?