The scene in LSL 1 when Larry buys the condom at the convenience store, the store manager yells out the choices you made for your "lubber", resulting in random people popping out from behind store shelves to mock you for it.
Crowd: WHAT A PERVERT!
From the same scene, you can make a choice regarding the size. Only "Large", "Giant" and "Gonzo" are available, but no matter which one you pick, he'll always say "small-sized".
Also from LSL 1, the censored sex scene with the hooker.
LSL 7: As Peter Purser finishes up explaining the rules for the Thighs Man Trophy contest:
Peter: ...are there any questions?
Crowd: Are there any answers?
Peter: *annoyed* You may begin.
When opting to seduce Peggy.
Narrator: *flatly* Larry, a penis is a terrible thing to waste.
Even attempting to use a pick up line makes it clear Larry DOESN'T want her.
Larry: *thinking* Nooooooooooo...
Attempting to "look" at Peggy's chest will cause Neil Ross (the narrator) to break character and refuse to read the intended line, calling out Al (who can be heard laughing in the background) and claiming he has "standards".
Farting around long enough after you've won the contest will result in this friendly little reminder from the ship's announcer.
Ship Announcer: LAFFER! GET YOUR ASS UP TO CAPTAIN THYGH'S CABIN!
After winning the contest and meeting Captain Thygh, she refuses to participate as she's filled with ennui, but Larry is obviously confused as to what she means. The narrator then gives the definition of ennui (boredom), explains the word's origins, and uses it in a sentence. Larry isn't the only one who hears him.
Captain Thygh: Who the hell is THAT?
Larry: I don't know. But I hear him all the time!
LSL 8: "Lesbian Nights" — a parody of "Summer Nights" from Grease where Larry and Ione sing the story of their date from earlier in the game and how it traumatized her into out-and-out lesbianism.
Earlier, when Ione starts chewing Larry out for what he did, he attempts to deflect her criticism by blurting out "I'm gay!" We then get an I Knew It reaction...from Larry's own crotch.
One of Barbara Jo's conversations where Larry uses puppets to try and calm Barbara down, especially if you get some of the wrong options.
When Larry Lovage and Morgan plays some unspecified Tabletop Roleplaying Game (although It's obviously intended to be D&D, given the sheet design shown) Larry's solution to saving a princess from becoming a virgin sacrifice is to make sure she's no longer a virgin.