In the late 19th century, two women who lived together without male support were said to be in a Boston marriage. Some, but not all, were lesbians, and they were independently wealthy or successful in the arts. Not so in Pandora Productions’ interpretation of David Mamet’s “Boston Marriage.”

Here, the leading ladies are in a long-term relationship, but live separately. Anna (Julia Leist, in an impressive professional debut), a woman of a “certain age,” lives in a fine house with the obligatory maid (Gail Kingsley). Anna makes her living as a married man’s mistress. She provides for her younger lover, Claire (Leah Roberts), with her “protector’s” favors. These women are not independent, and contribute nothing to society.

    This play is a departure for Mamet, who’s typically known for crisp, vulgar dialog, as in “Glengarry Glen Ross.” He apparently was channeling Oscar Wilde, as “Boston Marriage” is filled with great wit and words you see only in crossword puzzles. Thankfully, the program contains translations of the highfalutin’ terms, like “rodomontade” (pretentious boasting), “ukase” (a self-styled guru’s edict) and “reticule” (a drawstring purse). The play may be all dressed up in great-grandma’s clothes, but under the pretty costumes, wigs and wags, Mamet exposes the underbelly of marriage.

    Anna and Claire constantly barter (as all married couples do) amid banter, yet can’t live without each other. They were once passionately in love, but now Claire negotiates with Anna to use the house for an assignation with her new love, a tender young girl. Anna agrees only on the condition that she be allowed to participate. No, not in a threesome. Rather, Anna wants to “set the stage,” and declares: “We must have a pie. Stress cannot exist in the presence of a pie. It can out stress as the heat of the hand repels quicksilver.”

    Catherine, the Scottish maid, provides comic relief. Anna so disdains her maid that she can’t be bothered to remember her name and nationality. Both women taunt her mercilessly. They denigrate her sexuality, intelligence and heritage, which they insist is Irish.

    Leist spews Anna’s venom wickedly, while letting us glimpse Anna’s vulnerability. Roberts, last seen in “The Great American Sex Play,” responds to Anna’s barbs with perfect timing and holds her own in the marital sparring match. The actors are dynamic together, slowly turning up the heat until they’re on fire before intermission. Director Michael Drury’s staging is right on target. Kingsley is delightful as the put-upon maid.

    Mamet himself disappoints, however. He seems to have dashed off the plot as an afterthought, or is simply ridiculing drawing room farce. Implausible twists and turns abound, as the ladies connive to keep Anna’s income stream flowing. The plot may be unrealistic, but the rapier wit nevertheless engages.