Pulp Covers

He offered her to the highest bidder — the price — another man’s wife

From the back:

They devised an ingenious scheme whereby they would switch beds at night, not dreaming that in seducing the other’s mate, they courted blackmail.
It all started while on vacation. They had rented adjoining cabins and had improvised a shocking schedule of nocturnal exchanges—their brides the product of barter. Strangely, the wives accepted the arrangement with surprising delight. Yet in this mockery of marriage lay a hidden danger—blackmail and sudden death.

He was clawing at the delicate lace now.
“Carl, what are you doing?” she asked in
anger.
His answer was a renewed attack at the restraining fabric. She was lying on her side. Now, as she turned over on her back, he pulled her into his embrace. His mouth, moist and demanding, silenced her protests. Then suddenly came her surrender and the response to his ardor. She gasped and moaned in excitement as his hands explored the intimacy of that which she now would give him willingly—even wantonly,
“Carl! darling Carl,” she whispered. “I’ve never known how sweet and wonderful it could be.”

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