I can't get over a woman who has a boyfriend because she treats me like she's into me...what do I do? Wait?

Ask her. Tell her that you're not comfortable getting between her and her boyfriend. She will back off unless she is really serious. If she is really serious, think about whether you want to go through with this, and either point-blank refuse her, or ask her to tell her boyfriend about you. She may be lying to him abut her sexuality, and if so, you'll be ending a relationship built on lies that would never have worked. Otherwise, he could be fine with it, in which case go ahead. If their relationship is dying, this may be a good way to put it out of its misery. This may cause damage to the boy if she isn't very good at handling the breakup, so consider whether he'll take it well in deciding whether to go through with this, but in that case he won't enjoy a relationship with a cheating partner anyway.