Harvard’s Humanist Chaplain Greg Epstein has embarked on a second career as the host of a reality TV show. Called “Married at First Sight” and airing Tuesdays on FYI (formerly BIO), the series follows three couples who, after being scientifically matched, meet each other for the first time on their wedding day. Epstein’s role is to provide spiritual guidance for the newlyweds. He’s one of four “experts” — a psychologist, sociologist, and sexologist are the others — who counsel the couples over a period of six weeks before they eventually decide whether to stay together. “When I was first contacted I thought [the producers] had to be completely insane and out of their minds,” Epstein (inset) told us. “They kept me on the phone just long enough for me to go beyond the sensational title and see that it’s a serious look at [the couples’s] lives and their struggle to find love.” Predictably perhaps, the show, which is based on a Danish series, has been met with snark and skepticism on the Internet. One of the newlyweds is no stranger to reality TV. Jamie Otis, who appeared on the 2012 season of “The Bachelor” with Ben Flajnik and the spin-off, “Bachelor Pad,” is taking her chances with the extreme social experiment. Maybe the third time will be the charm.