Lois: Aha! No coaster. Look at that ring. That is why I have to move out of this house.
Malcolm: Mom.
Lois: Every time you boys thoughtlessly mar the furniture by refusing to use coasters, what are you doing?
Boys: Killing the baby.
Lois: Killing the baby. Every time you run through the house, every time you destroy furniture, every time you fight with each other, you are killing the baby.
Hal: Lois, the doctor just said you should avoid stress.
Lois: Which is just medical jargon for the simple fact that every time you boys misbehave, you might as well be taking a knife and putting it in that baby's tiny little heart.
Malcolm: Will you stop saying that?
Lois: I just hope you boys have the character to channel the horrible guilt you should be feeling Into better behavior while I'm gone.
Boys: We're sorry.

Otto: Helga, this cheese is magnificent. [laughs] Would you like to try just a little bite? No? How could you not like cheese? It is made from something that comes from you.
Francis: Hey, Otto.
Otto: Ooh. Francis. Have you seen Helga's squeaky toy? It's the one that looks like a little fire hydrant.
Francis: No, but I did get in the new branding iron.
Otto: Shh. Do you want to scare the poor thing out of her wits?
Francis: Otto, I know how much you love Helga, but we have to do this. All the cows have to get branded and de-wormed. I promise I will be very careful.
Otto: [fretful mutter] But don't tell her about it. You know, she is not as brave as she looks. I told her one ghost story around the campfire, and she had to sleep between me and Gretchen for a week.

Malcolm: Mom, don't do this!
Lois: Malcolm, in a few days, I'm going to be gone for a very long time, and I need to know that you're okay. We are going to have this talk. I know about you and Nicki.
Malcolm: I'm not seeing Nicki! I'm not having sex! I know about protection! I know all that stuff!
Lois: Malcolm, there's a lot more to being a sexually responsible person than what they teach you in health class. It's very different when you're experiencing it yourself.
Malcolm: Mom, stop. I'll do anything you ask. Just don't have this conversation.
Lois: Oh, honey, it's going to happen.
Malcolm: [groans] No.
Lois: You think I like it? You think I like the embarrassment we're going to be feeling for the next few hours? But, Malcolm, I have no choice. I cannot be there when you are having sex.
Malcolm: God!
Lois: So I'm going to try to give you the benefit of my experience. I'm going to bury you with every piece of information I have. I don't know what will be helpful and what won't, so I'm just going to tell you everything.
Malcolm: Oh, my God!
Lois: The sooner we start, the sooner it'll be over with. Now, this is a diaphragm.

Reese: I can't believe we're locked out. Mom won't be home until 6:00.
Malcolm: Hang on. I know how to get in. [picks up hide-a-key rock] Here it is.
Reese: I'll do it. [throws rock through glass and unlocks the door] Thanks. That credit card thing takes hours.

Lois: [to Malcolm] And believe me, it's a lot more sensitive than most men understand. A little bit goes a long way.

Francis: Otto, I have to tell you something.
Otto: Francis, have you seen Helga?
[A waiter brings Otto's meal: carrots and peas, a baked potato and a steak]
Francis: No, I haven't.
Otto: It is not like her to wander off alone. [cuts steak] I'm starting to get scared. Mmm! This is delicious. [chuckles] Do you think she ran away because she was angry with me?
Francis: I don't think so.
Otto: Well, I should have been there when you branded her. [eats steak] I could have held her little hoof. [chuckles] So tender, so moist. You must try some.
Francis: Mm-hmm. [forced chuckle]
Otto: Look at me, enjoying myself while my Helga is out there, alone and scared. That is it. I will go, and I will look for her, and I will find her, if I have to spend all night searching!
Francis: Otto, if I don't say this right now, I am never going to say it.
Otto: Yes, go ahead. Pass the Bearnaise sauce, please.

Lois: And people, they hop from one person to another trying to get some sense of validation. They do this all through college, all through their twenties, having all sorts of casual encounters. And sometimes they even convince themselves that the relationship is serious because the sex is so great, but that...
Malcolm: Wait. Stop. What did you mean by validation? Validating what?
Lois: Well, sometimes people will attract other people just to prove to themselves that they're likable. And if that's the reason that you're having sex with someone, you can cause a lot of damage.
Malcolm: But if you want to have sex with someone, doesn't that mean you really like them?
Lois: Oh, no, honey. That's exactly the trap people fall into. You see, a lot of people...

Reese: Oh, my God. I don't think I can keep this up.
Malcolm: It's just a few more days until she leaves. We can laugh all we want when she's backing out of the driveway.
Dewey: We're not really hurting the baby, are we?
Malcolm: Please. A week before you were born, we tied our playpen to the back of her car and followed her to work. She's just trying to save face.
Reese: She doesn't want to admit that we actually drove her from the house. And now we're in charge. [chuckles]

Lois: You were with that girl, weren't you?
Malcolm: No! I was at the library studying.
Hal: You were supposed to pick your brother up at school.
Dewey: There were rocks. There was a beehive. But where were you?
Lois: You are not allowed to see that girl.
Malcolm: Her name is Nicki, and I'm not seeing her.
Lois: Every time you lie to me, it is like you are digging a tiny little grave.
Malcolm: I am not lying to you!

Reese: [door slams] Hi, Mom. Hi, Dad. [sirens approaching] You know, Mom, you're looking lovely today. [talks louder] People don't appreciate how lovely you can be in the right light. I'm always telling kids at school that I have the loveliest mother.
Lois: I'll put on the coffee.
Hal: It's Henson. Make decaf.