If Q was less of a cocky little bitch Janeway might have been more tempted by him. If he had actually gotten them home she might have noticed his interesting and erudite qualities instead of only seeing his annoyingness. But I think that's a big part of why he doesn't take her home, because he needs her to need him. If he took them home she would need him for nothing.
NOW when he visits her in her bath and bedroom she has to at least go through some motions of tolerating him because she knows he can take them home any time. He's mercurial and though she doesn't believe he will ever actually do it it's in her face every moment he's there that he could do it. And maybe there's some kind of magic response she can give him that will make him do it but she hasn't discovered it.
A normal, healthy person would think "I will give this woman what she wants, what she actually needs and she will respect me, and possibly even love me for it."
Q thinks, "If I never give this woman what she wants she has to keep talking to me in case someday I do!"
So. If Janeway had leaped into the red velvet bed and said, "Take me Q oh take me now!" would he have magiced them home one second later when they were done? Would he ever
have magiced them home?
What would it have taken for this to happen?