Translation from your friendly neighborhood weeb:
Original pixiv title: "Marnie, super embarrassed after being seen dressing up as Morpeko in secret"

Marnie: "I-it's not what you think! Jeez! It's not like there's anythin' wrong with it.*"

SFX: There's a bunch, but they're all basically cute flustered noises.

TL note: Marnie has a Kyuushuu dialect in the original japanese games, and so the English localizers gave her a slangy manner-of-speech (like I did here) to express that. Personally, if she were actually voiced, I'd give her a Cockney or Welsh accent (like Zeke/Nia from XC2), which better represents how Kyuushuu dialect distorts and changes standard Japanese.