Entropy
From Buffy Cross & Stake - AngelX

Ep: 18.

Having accepted the offer to become a vengeance demon again,
Anya attempts to curse Xander for the pain he caused her...but she
can't do it herself. Instead, she secretly enlists the help of
someone else and it doesn't go how she expected.

 

Since Xander and Anya’s wedding fiasco the two have had time to

reflect and both miss each other a lot. But the situation turns ugly

again when Anya and Spike, both feeling spurned (and the affects

of a lot of whisky), sleep together…and Xander and Buffy happen

to witness it.

The Trio have been following the Scoobies everywhere they go
with hidden cameras. When one camera is discovered and the rest are
traced, what some characters see on video proves to be devastating.

Buffy tries to spend quality time with Dawn to make up for her
violent actions in "Normal Again" (if you consider trying to kill all
her friends violent), but Dawn's idea of time well spent is the
dangerous world of patrolling.

Buffy confesses to Dawn about her relationship with Spike and
after an odd turn of events, Xander and Anya find out as well.

Dawn's stealing is readdressed.

After some sweet time spent together after class and a during
coffee date, Willow and Tara do get back together and make with the
major smoochies.

The Trio steal a disk needed for one of their upcoming big evil
plans.