itch.io

You have to progress through the Mansion quest line. And throughout the mansion you can collect the whole outfit for free

After the quest you can buy the Maid and Butler outfits 

So its annoying the hell outta me but I can't get Linda to come to the ruined lab you start the game in. I've finished the Meat Parasite part of the quest and interacted with the Tubes unless they're separate ones on the higher floors i somehow missed