Tension & living together relation

unmarried person who is 40 yrs came into my life with lots of love, He is good person of this world, so my family agreed for our marriage also, So before marriage itself we had relation with each other, thinking that we will be marrying very soon, But My self 35 yrs widow last my husband in the age of 23, having now 11 yrs old son, So decided not to marry till these years.now i feel to marry this person. When he said to his mother that he is going to marry 34 yrs widow having 11 yrs old son, she refused for our marriage, she started threatening to kill herself if he marries me,His mother is having mentally disorder.we think.. thats y she is not ready to listen anybodys words shouting like anything with all. by that this person is afraid that he may loose his mother & he loves his mother a lot, same way he is ready to live with me but without marriage.for that i am not ready.