I'm actually somewhat disappointed with this chapter. It was going well up to the point where they spread the rumours and Bai heard it, but her plan afterwards is just stupid. If you hear you're the real romantic interest of someone, why the hell is your first idea to put drugs on his tea? Shouldn't you simply aim for a 1 on 1 private talk where he "doesn't have to pretend to love someone else"? ugh.
I think the reason this arc feels so long is because the author keeps developing all plot lines at once, advancing each one at a snail pace. I'd prefer to sink one "enemy" at a time instead of seeing ex-husband's monologues in-between the bai ting stuff, since he doesn't seem to even need to be there. It's not like he needs even more reasons to miss Luxia, he already does.