Proper ladies and gentlemen

What if our favourite Crawleys had met before the famous introduction at Crawley House? You see, I always felt that Matthew "overperformed" just a bit to express his embarrassment of having been overheard and in awe of Mary's beauty. So what if he had reason to be truly embarrassed? And why did Mary so very readily succumb to Pamuk's persuasion in her bedroom? Mary's POV.