Actually, they took a fair bit of time before she and Jake got comfortable on a personal level from what I've seen. After "Evicted", we still have "Henchman" (where he tried to kill her and "It Came From The Nightosphere" (where he largely was not present).



It wasn't really until "Go With Me" that they were shown on screen together relatively amicably and not until "Heat Signature" that we really see them hanging out as pals.



Not it to mention whatever slice of their life happens off screen, and any interactions in that time that we might not have seen. I imagine it took a lot Of convincing from Finn to get Jake to hang out with her for the first time after "Henchman" without carrying a stake and some garlic.