I'm a little curious at what chapter in the novel the main character will say to Lu Feng, ...

He doesn't! Lu Feng knew from the start An Ze wasn't human which is why he took him to be tested by the doctor at the start. An Ze finds out Lu Feng already knew in chapter 38 of book two

Uhhhh there's 90 chapters in the novel, don't underestimate Lu Fengs intelligence. I don't remember when it was explicitly stated but we can tell Lu Feng figured something out way earlier, but still after this arc

Ahhh I seee thank you for the answer ヾ(❀╹◡╹)ﾉ~

Ah I see I see, then I cannot wait to see an zhe reaction to this XD. Oh I have one question, is there any specific reason why Lu Feng doesn't kill an zhe immediately besides he thinks an zhe is weak and doesn't possess any threat to other human ? ( if the answer contains major spoiler you doesn't need to answer this question)

I'm actually doing a reread rn trying to remember the answer to your first question (and this series is great so def rereadabable worthy.) but I can answer this one. It's never explicitly stated, but as you can tell initially, Lu Feng suspects MC. Then he believes MC is human. Then something inexplicable happens and he suspects MC again (probably 10-15 manhua chapters from now). This time taking some precautions (you'll see what I mean later). But also I believe he has gathered feelings for MC by this point. Which makes sense since Lu Feng is a very lonely character.

I don't consider these spoilers because MC has been planning it since chapter one, but eventually An Zhe is able to find an opportunity and steal back his spore, and then escapes the human city. Lu Feng has thought about killing him multiple times, and always stops. I think it's because MC has a cute naivety. Innocent yet very mature and logical. A line from the book from Lu Feng about An Zhe about their first meeting when Lu Feng kills the man who helped An Zhe enter the base: "There was a naive calm in the sorrow, as if as long as Lu Feng gave a reason, this person would accept everything and forgive everything."

Also, we're only about 1/3rd through the story. There's no saying that Lu Feng doesn't end up actually killing An Zhe once he finds out An Zhe isn't human. You're gunna have to keep reading to find out :P.

There's no real answer to this unfortunately. I do have a lot of my own theories though (will leave out the ones that involve spoilers)

1. His instincts are just THAT good. He's got a 100% rate of telling whether someone (human) is infected or not. Technically An Zhe isn't because he's a mushroom and maybe Lu Feng somehow knew he wasn't human but also knew he wasn't infected so he got him tested for confirmation.

2. An Zhe is told multiple times by others he behaves strangely as if nothing around him affects him. Maybe this made Lu Feng curious? He probably behaved conpletely different to everyone else the first time they met by not being afraid of him

3. He just thought An Zhe was cute. Lu Feng seems to naturally be a very hopeful person who wanted to protect humankind but needed to make difficult decisions (like killing the infected) when neccessary. His heart may have just wavered for the little mushroom purely because he's just so cute

Woowww thank you for the long answer now I'm more excited to read the novel and also the power of cuteness melt the icy heart

Now I really want to read the novel more, thank you for the long answer btw it's seems no one can resist the power of cuteness from our little mushroom