the undetermined effusions of gallantry and good breeding

In his return with Emilia from the opera, though he still maintained the most scrupulous decorum in his behaviour, he plied her with the most passionate expressions of love, squeezed her hand with great fervency, protested that his whole soul was engrossed by her idea, and that he could not exist independent of her favour. Pleased as she was with his warm and pathetic addresses, together with the respectful manner of his making love, she yet had prudence and resolution sufficient to contain her tenderness, which was ready to run over; being fortified against his arts, by reflecting, that, if his aim was honourable, it was now his business to declare it. On this consideration, she refused to make any serious reply to his earnest expostulations, but affected to receive them as the undetermined effusions of gallantry and good breeding.
This fictitious gaiety and good-humour, though it baffled his hope of extorting from her an acknowledgment of which he might have taken immediate advantage, nevertheless encouraged him to observe, as the chariot passed along the Strand, that the night was far advanced; that supper would certainly be over before they could reach her uncle’s house; and to propose that he should wait upon her to some place, where they might be accommodated with a slight refreshment. She was offended at the freedom of this proposal, which, however, she treated as a joke, thanking him for his courteous offer, and assuring him, that when she should be disposed for a tavern treat, he alone would have the honour of bestowing it.
Her kinsman being engaged with company abroad, and her aunt retired to rest, he had the good fortune to enjoy a tete-a-tete with her during a whole hour, which he employed with such consummate skill, that her caution was almost overcome. He not only assailed her with the artillery of sighs, vows, prayers, and tears, but even pawned his honour in behalf of his love. He swore, with many imprecations, that although her heart was surrendered to him at discretion, there was a principle within him, which would never allow him to injure such innocence and beauty; and the transports of his passion had, upon this occasion so far overshot his purpose, that if she had demanded an explanation while he was thus agitated, he would have engaged himself to her wish by such ties as he could not break with any regard to his reputation. But from such expostulation she was deterred, partly by pride, and partly by the dread of finding herself mistaken in such an interesting conjecture. She therefore enjoyed the present flattering appearance of her fate, was prevailed upon to accept the jewels which he purchased with part of his winning at Bath, and, with the most enchanting condescension, submitted to a warm embrace when he took his leave, after having obtained permission to visit her as often as his inclination and convenience would permit.