This is an interesting question @Real_Screamer and to be more accurate, I have never had a time where I did not have an outlet for my sexual needs. I have never been without a way to satisfy my sexual needs because of being able to and enjoying masturbating. I have always loved to masturbate and I still do in addition to my sex life. The masturbation does satisfy my sexual "need" at the time.
But what you might want to ask, or differentiate, is the desire or need for intimacy that comes with sex. Now that is something that is not so easy to satisfy through masturbation alone, although masturbation will go a long way to help dull that ache. I do see that you have specified the loss of a spouse as being a loss of sexual needs and I think you are right about that except that sexual needs are different than need for intimacy. I hope to never lose my husband and that is something I do not want to ever experience. I want to be the one to go first but that is not for me to decide.
As I have aged, I have left behind those mores imposed by religion and society and the "good people" who love to pass judgement on others. Actually I put those behind the moment I posed nude for my husband and even more when we posted them on a web site. The only thing that limited me with continuing was, again, society but only because I did not want my children and relatives to have to deal with my "pornographic" side.
When I was younger and if I am honest with myself, I held back on giving my husband his ultimate release with me because, back then, good girls were not supposed to enjoy sex. It was a duty or a chore or a service but my body with my husband told me that it was just not so and the more I was with him and the older I got, it was all about satisfying both of us. Then when my "porn" days were here and we had family friends help with some of the photographs, I took on another "sex" partner because of the nature of the project we were shooting. At the first our friend "Walt" was there as a "stunt cock" and when the picture taking was done he was on his own to get relief. But it was not long before I saw that neither one of us was totally professional about what we were doing, we quit, or I quit, pretending that it was just a job and when or during the photo shoot was over or happening, I wanted Walt to have his satisfaction between the two of us.
Fast forward 25 or 30 years and I joined zity.biz and I have found that intimacy, not just sex or masturbation, is a driving force for me. My only regret is that I did not start sooner and learn earlier that masturbation and sex and intimacy are separate things all by themselves. But put them together and that is what it is all about.