Well, there is always that weird ending that leads with you waking up to her making you breakfast. You can get that two ways even. One of the ways is by choosing to not let her go, after which she says she's going to do something to make the choice better for you or something, then your vision goes red and you wake up on the couch with her calling you honey, making you breakfast in an apron, etc.
I think that's the closest you'll get when it comes to living happily with her. But the same time, were you even paying attention? Because even in the ending where you supposedly let her go, what the hell is that whole thing where there's like a Time Skip and his phone glows white again out of nowhere and then all the sudden Mal0 is back and helping him and his friend find her sister, who is supposedly trapped within an animatronic that also serves as a little shout out to one of Night Fox Works other games.