Since Sam was single, it would not have been an "affair" if he got together with Ina Coolbrith in San Francisco. I went hunting one day awhile back never found an answer to the question on detail of their relationship, other than rumor.
That he did care about her is indicated years later, following the 1906 SF Earthquake in which she lost everything. George Wharton James was leading fund raising to help her. In the East, James burst in on Twain, told Twain he had made an appointment with a local photographer to have some photos taken which he (James) would sell and give the money to Ina. James had another appointment, and left; Twain followed through on getting to the photographer. According to James' account of the incident, he did not interview Twain; there is no evidence James ever interviewed Twain, though he wrote several articles about Twain.
    On Wednesday, May 8, 2019, 6:03:03 PM PDT, Arianne <[log in to unmask]> wrote:  
 
 Out of the blue, someone asked me, as if I'd know and I don't, whether Ina
and Clemens had an affair in S.F.  She is said to have been involved with
him and Brett Hart, perhaps as colleagues, in the early  1860s.  I think
she also was a writer.  Apparently she moved to Oakland and became a mentor
(or something) to Jack London.

Let me know if any of you can enlighten me.

THANKS
Arianne Laidlaw
-- 
Arianne Laidlaw A '58