I'll jump on the bandwagon here and say go - just go.
IMO, expending the energy for revenge just shows he/she got to you, and makes common friends lean toward their side when they wouldn't otherwise. Finally, revenge seems fun in the short term, but a bit sophmoric with a few passing years.
In more years of being married than I have fingers and toes to count on, I've come to decide that trust (honesty, whatever) of your partner is more important than lust or love (altho the former sure is fun
).