Marrying another woman without telling the first wife
I'm married to a woman (45 years old) that is almost 4 years older than me & we have 2 daughters. Due to the early removal of her uteris (womb) at the age of 37, her sexual abilities droped dramatically. Sex is very important for me in quantity & quality, which is not currently present due to my wife's case; At the same time, she doesn't accept the idea of me marrying another. She said divorce me & marry another; & she means it.this will mean the destruction of a family with 2 kids at a very critical age. Also I do love my wife & care for her. Is it ok to marry another secretly without telling her in order to avoid falling into sin.? Furthermore, what are the measures i should take care of in order to have a marriage that complies with Islam.? Is the Time bound, Mesyar or Mot3a marriage approved by Islam.?