So, X.B. stands for XPUCTOC BOCKPECE (khri-STOS vos-KREH-seh), which, in English, means "Christ is Risen!" It's the Paschal greeting, to which the proper answer is, "BOUCTUHY BOCKPECE" (vo-EEST-ih-nu vos-KREH-seh), which means "Truly he is risen!"
Church was very nice. There were probably upwards of 400 people there when the service began around 11 p.m., so it was good that Fr. Vladimir decided to have the service outside. The Greek deputy chief of mission (second to the ambassador) was there, and when the choir sang the Paschal hymn, "Christ is risen from the dead," in Greek, he joined in enthusiastically, which was very endearing. The police were there too, outside the fence. I presume they were there to keep people from harassing us, as they didn't seem to have any other purpose (they themselves were not harrassing us). I was hit on for the first time ever during a Pascha service (though not for the first time during any service - during my first and only trip to an Armenian church for Sunday services, a man tried to butter me up, then groped me). This time, the young man in question spent a good hour trying to butter me up by professing interest in Orthodoxy (he was Armenian and not Orthodox), following me around during the procession around the church and asking all sorts of questions about the service. It was only once he began waxing poetic about my beauty that I finally told him to get lost. I also met an Armenian-Russian-American woman from LA whose parents (one Armenian, one Russian) were from Sukhumi, and who was visiting a relative for Pascha.
Despite the several abnormalities (service outside, the mack-daddy), Pascha in Armenia was Pascha. That's one of the nice things about Orthodoxy - the service is the same, so no matter where you go, you are always home.