The quote you mention has been brought up before; it's from the Season 7 episode "Never Leave Me." The full quote is as follows:
SPIKE: I'm not talking about the cellar. The people in the cellar got off easy. I'm talking about me. Buffy, you have never met the real me.
BUFFY: (crosses arms) Believe me, I'm well aware of what you're capable of.
SPIKE: No, you got off easy too. (stands) Do you know how much blood you can drink from a girl before she'll die? I do. You see, the trick is to drink just enough to know how to damage them just enough so that they'll still cry when you— (chokes up) 'cause it's not worth it if they don't cry.
BUFFY: It's not your fault. You're not the one doing this.
SPIKE: I already did it. It's already done. (paces, then steps purposefully toward Buffy) You wanna know what I've done to girls Dawn's age? (beat) This is me Buffy. You've got to kill me before I get out.
Contextually, this scene is Spike trying to convince Buffy to kill him, because he's been killing people unknowingly. I think he thought of the worst thing he could possibly imagine that might prompt her to do so, & the fact that it was the implication of raping young girls, means that *he* thinks that's the worst thing he could possibly do. I think the chances of him actually having done so are less than slim-to-none, particularly as, like I said, he's going to say anything to convince Buffy to kill him. Considering this is literally the *only* time anything even vaguely like sexual assault has been mentioned in his past, & the complete context in which he says it (ie: trying to convince Buffy to kill him), it just never struck me as based on anything actually true.
Thanks for commenting (even years later! ☺)
ETA: Thanks for noting the incorrect episode numbers! I think I must have typoed one wrong & then just continued from that count. I'll fix it up.
Re: Mostly agree!
SPIKE: I'm not talking about the cellar. The people in the cellar got off easy. I'm talking about me. Buffy, you have never met the real me.
BUFFY: (crosses arms) Believe me, I'm well aware of what you're capable of.
SPIKE: No, you got off easy too. (stands) Do you know how much blood you can drink from a girl before she'll die? I do. You see, the trick is to drink just enough to know how to damage them just enough so that they'll still cry when you— (chokes up) 'cause it's not worth it if they don't cry.
BUFFY: It's not your fault. You're not the one doing this.
SPIKE: I already did it. It's already done. (paces, then steps purposefully toward Buffy) You wanna know what I've done to girls Dawn's age? (beat) This is me Buffy. You've got to kill me before I get out.
Contextually, this scene is Spike trying to convince Buffy to kill him, because he's been killing people unknowingly. I think he thought of the worst thing he could possibly imagine that might prompt her to do so, & the fact that it was the implication of raping young girls, means that *he* thinks that's the worst thing he could possibly do. I think the chances of him actually having done so are less than slim-to-none, particularly as, like I said, he's going to say anything to convince Buffy to kill him. Considering this is literally the *only* time anything even vaguely like sexual assault has been mentioned in his past, & the complete context in which he says it (ie: trying to convince Buffy to kill him), it just never struck me as based on anything actually true.
Thanks for commenting (even years later! ☺)
ETA: Thanks for noting the incorrect episode numbers! I think I must have typoed one wrong & then just continued from that count. I'll fix it up.