From what I have read, it seems as though he was romantically involved with Margaret, with maybe some sexual activity occurring, however, it has been stated that there wasn’t a great amount of emotional value in their relationship. Polly, on the other hand, was a student of Franklin during his extended periods of residency, and the two would flirt constantly with each other. There was even a sketch that was drawn of the Franklin and, presumably, Polly kissing in the flat. Polly was even there next to Franklin on his deathbed in 1790, traveling from London. So I conclude that Franklin was romantically involved with both Margaret and Polly Stevenson.