The crazy pick-up lines in Parade's End

The hysterical pickup lines in Ford Madox Ford's Parade's End, beginning with Tietjens's come-on to the probably virginal Valentine Wannop on the eve of his departure for the front: Will you be my mistress tonight? Hey, it worked for him (sort of), so how could you top that? How about with the foppish Perowne, coming on to Tietjen's estranged wife, the insufferable Sylvia, with this: Please leave your door unlocked tonight. (I may have the phrasing wrong.) That's a good one, made even better by Sylvia's retort: Whatever for? No other word for it - she's a bitch. She pretends not to understand so as to taunt Perowne, yet she's with Perowne just to taunt estranged husband, and she's wrangled her way to the Rouen outpost where he husband is stationed so as to be with him, against regulations, and taunt pretty much everyone in the British and Canadian armies with her beauty and accessibility. She was perfectly willing to use Perowne - twice, actually - first running off with him for three weeks, then returning to a miserable life with T., each of them unwilling to divorce, he on principle she on relgious grounds. Now in vol. 2 she uses Perowne to sort of smuggle her to the French outpost - he has some cushy, safe, debonair job as a courier, bringing crap like boxes of chocolates back and forth to high-ranking officers. He brings her along on his arm - he gets waived through customs, and she it turns out has no papers (he never asked). Now, she waits to see her husband, but when her arrives at the one classy hotel in town she's there flirting with Perowne - she knows her husband sees them together, they look at one another through "the glass" (there are mirrors everywhere, probably an Edwardian decor detail long gone, and picked up well in the art design of the great BBC-HBO miniseries); instead of walking 20 feet to her and giving her a piece of his mind, T. sends her a note, via a servant, which she ignores. So there they go again, these crazy people - she's travled a great distance at some risk to see her husband and they stand 20 feet apart and ignore each other, the two most stubborn people in the world. She does take advantage of the situation, though - taunting Perowne about his manlihood, about how T., no brute as far as we can see, will beat him to a pulp, that T. has a real military assignment (true) while Perowne has a cushy job, that she hated her three weeks running off with P., in short making him feel useless and emasculated in every way. But he's still nuts about her, and even T. is trying in some way to hang on to her, or at least to their marriage. Whatever for?