Ignorance is Bliss
Ever wonder what it might have been like if Milly and Meryl had known what was going on from the beginning? Well, I have. Ever since I heard Meryl utter, "Why did a nice person like Mr. Wolfwood have to die," I've wondered. I'm not saying that Nicholas wasn't nice, but neither Milly nor Meryl truly knew Nicholas or Vash, and therefore I have to wonder if Meryl would have put that sentence a different way if she had known who and what Nicholas was.
It's pretty obvious that I don't like the idea of the insurance girls being with Vash and Nicholas--actually I'd rather those two be together than anything else, but Vash admitted he doesn't like sleeping with guys, and it's obvious that Nicholas feels the same way. Getting to the point, let's just imagine for a moment that Nicholas didn't die, and approached Milly and told her about Chapel, the Gung Ho Guns, and his involvement with both. How would Milly react if she found out that Nicholas had been a killer and wasn't the nice guy she had believed him to be? Yes, he is good with kids, yes he has a heart melting smile, but underneath all that is a sad, lonely, and confused person. So maybe Milly latched onto the gentleness within Nicholas, and believed that was all that mattered and was the strongest quality about him. The problem is though that she sees that sweet guy who's good with kids, not the confused man who's trying to figure out why he's on that foresaken desert planet, and why he's beginning to feel as if everything that Chapel taught him was wrong. In essence, Milly is helping Nicholas to continue escaping from reality--something that he feels very strongly about, and hates. Note that Milly really didn't help much when Nicholas was miserable about killing Zazie the Beast. She just told him that he was right as was Vash, and then she fed him, and let him cry on her shoulder. That wasn't what he wanted. He wanted Vash to tell him that he was either right or he was wrong, and to tell him that everything was going to be okay, because it was a mistake and mistakes can be forgiven. If Milly found out the truth about Nicholas, given her actions throughout the show, she would slap him hard and then never speak to him again, because he was a liar. I came to this conclusion because she sees everything in black and white. You're either wholy good or completely bad, and Nicholas lives in the gray area. Meryl probably would be shocked to find out that Nicholas was leading Vash to Knives, and that it was partly because of them that Vash found Knives, and her time with Vash was coming to an end. Meryl would hate Nicholas as well.
Vash also never tells the insurance girls the whole truth. In episode 24, Vash simply tells Meryl about Knives, and any details directly concerning his quest for Knives. He does not tell her that he is imortal and a plant. I think the prospect of Vash's eternal life might frighten Meryl off, but if she truly loved him then she would come back. However, Vash--after his fight with Knives--has a very big job to do. He has to force his brother to work with him, to create a more liveable environment on the planet. He has no time for Meryl. I also want to add the fact that throughout the entire show, Vash refers to the girls as, "The Insurance Girls," never by their first names. This is probably because he tries to distance himself from everyone that he meets. I will say this though, if you notice he does a horrible job of distancing himself from Nicholas. The two of them are drawn together like blood brothers. Also, the insurance girls are not exact clones of the guys. They're different enough to be different people, and really I think that's why they wouldn't go well romantically with the guys, but they do make good friends.
So in the end it probably was a good thing that the girls didn't know the truth about the guys. Otherwise the show would have been more complicated than it already was.Love & Peace