ouch. sorry. are you sure its a good idea to go away together? unless you think there's a chance you'll work stuff out on the trip, won't it just prolong everyone's agony?
It is awkward commiserating with one partner about a breakup with another, but its worth giving your partner the chance to comfort you - a sad person can come across, unintentionally, as distant and excluding when you're not communicating about the sadness.