[bigpooch]

Since this is a "donkament", capping on the end is best.
In a cash game, (unless it's maybe 1-2 or smaller) the
3-bet usually means they win most of the time against your
raise, i.e., they have AT LEAST a boat (if they don't, they
are simply "spewing").

In your spot, with JJ88K, it's a marginal reraise predraw
(at best) and highly depends on the range of the opener;
e.g., if he is opening with KK or any straight-flush draw,
your reraise is incorrect, but if his range is QQA and
includes not only straight flush draws but most A-high
flush draws, you should reraise. A bad feature about your
hand is that you hold a king, making it less likely that
the opener only started with a pair of kings.

If the situation was changed so that you were in the BB with
this same hand, the opener was utg and there was a cold
caller, as long as the cold caller doesn't frequently trap,
reraising makes much more sense. You obviously don't need
to have the best hand postdraw more than 50% of the time to
put in the third bet predraw, but you probably need a figure
more than 40% (it needs to be higher than 1/3 obviously)
because of the slight danger of a cap.