A Subtle Feeding?

[Becq]

Does he have to answer your compel right away? Like instantly start feeding on the children?

Consider the following feature of Emotional Vampire:

"Feeding Frenzy. When in the presence of heightened
emotions and willing victims, you feel a
nearly uncontrollable urge to feed. The GM
is within her rights to call for Discipline rolls
to resist the urge. In some cases, the urge may
take the form of a compel against your high
concept."

I'd take that to mean that the urge is very immediate ... unless you buy off the compel.

[Blackblade]

Does he have to answer your compel right away? Like instantly start feeding on the children?

I'd think that would be something that could be negotiated during the compel.  If the WCV has high discipline, it would make sense that he would be able to control himself long enough to get the rest of the party to leave. 

[noclue]

That's your play style though. I've seen this done both ways, and seen it succeed and fail both ways. The GM and players should play in a way that makes it fun for them. He probably knows his group better than any of us do.

I'm with Will.