Who knows. Konohamaru may very well have ill feelings toward Oro, but won't take it out on Mitsuki, who hasn't done anything to him, and didn't ask to be Orochimaru's son. Thus far, Mitsuki seems trustworthy and good. He's done no harm to anyone.
Well, lets say he knows Orochimaru's father. Naruto, being an idol of his, probably taught him a thing or 2 about forgiving. Sarutobi was the one killed, but even he seemed to mainly feel bad about Orochimaru, and disappointed, not hating him. As Kakashi said when facing Sasuke. He now understands how even when a student as fallen, you still love them.
And plus, grudges really are pointless. You can be as pissed as you want, but it only effects you, making you more angry and bitter. o you're poisoning yourself and expecting someone else to be effected by it. Look at Kisame vs. Gai. Kisame was still warm about that kick to the face from Gai in part one. And he's not let it go, and ticked off. Meanwhile, Gai doesn't even remember him. So what point did that anger serve, other than keeping him mad?
So best to try and understand - don't have to agree with them, just try to understand why they did such, and try as best you can to forgive and move on. Easier said than done.
