I think that we're meant to accept that "Bingley has great natural modesty" and is willing to believe that Darcy who is cleverer than him, has watched her and beleives that she has no special feelings for him. So if that's the case, why would he ask her? If D is right, surely it would be a bit awkward for him to go saying "So, Miss Bennet, I thought that you had feelings for me, my friend Darcy believes you dont.
I think that if D is right, then it only woudl embarrass Jane, if she was asked such a question or asked to marry him and she was obliged to refuse him because she didn't love him.
Yes the situation was that Bingley paid attention to Jane and she DID develop feelings for him, but given the delicacies of courtship at the time, unless he made a formal proposal, how was he to know for sure?
It IS possible that he felt "yes I am really smitten with Miss Bennet but she's so beautiful and sweet and charming.. She'd never look at a fellow like me. There are sure to be other chaps after her that she would like a lot better." and while he loved her, he accepted that he had not succeeded in winning her heart and went away to get over it.
I just dont think that he was dishonorable or culpable.. If so, then surely Wentworth is behaving very badly in Persuasion when HE pays attention to Louisa, and she falls for him a bit, and then he tries ot weaken her attachment by keeping away from her.
Poeple do fall in and out of love,and in today's world, we can talk about things and discuss the relationships more freely but it still doesn't alter the fact that not every attachment will end in marriage or a serious relatonship, or that people wotn sometimes be made unhappy through one person falling out of love, when one person remains in love...