Wife claiming that her first husband did not divorce her

Q: After married to a second husband for 20 years, the wife declares that she is no longer married to the 2nd husband because she was never divorced from the first. The 1st husband reclaims his wife. In the 1st marriage, no talaq was mentioned. The husband just stayed away from the husband. Is this allow in sharia and was the second marriage valid. What's the ruling on this?

Masturbation

Q: I am 21year old female. Please tell me if doing self pleasure is haraam in islam? If so then what are the physical effects of this habit? How can a female leave this habit?

Polygamy

Q: How does one view the issue of polygamy in the 21st century. What are certain advises given to someone who wishes to marry a second wife in these days without the support of the 1st wife and mother of the husband?