Now, that's a spoiler. Anyways, are they holding the hands of the MC or eachothers?
On Bella's path, if you broke up with Jill but kissed her in Episode 9, Bella will hold Jill's hand on top of MC's chest, although MC looks a little confused.
On Jill's path, if you got Bella's Episode 7 lewd, you have the choice to comfort her as she sadly looks at you and Jill together. You can hold her hand as well as Jill's, MC has a more positive attitude than the Bella version.
One thing to note is that on Jill's path, she is completely unaware that MC and Bella have a sexual history. And of course on Bella's path, Jill is still a virgin, but admitted to Bella she still has feelings for MC. So even a threesome is a little out there, but this is a good sign
something will happen.
Also,
Bella and Jill have had a sexual encounter in the past, that lays the groundwork for a possible threesome as well.