@colboh You should read this fanfiction because you will love it, and more as it is building that kind of relationship Yuri that I agree with you between Enty and Bel.
The fanfiction is not mine if not the respective author whose username on that page is Salvo519, and I'm reading that story but I'll give you the link so you can read it if you wish.
I don't think that there is such a thing that Homura could do that would drive her over the "creep" edge for Madoka... if the scene where Homura breaks down crying in front of Madoka while holding her wasn't it, nothing is.