Whether this (or lots of other things) is a sin is a matter of opinion; so you aren't necessarily going to get an authroitative answer here. There are certainly people in the world who would say it is a sin and other who say it is not.
From my personal perspective, the relevant question is: Does it harm anybody?
He never married and never had children even tho he had 2 serious relationships
No, no marriage and no children. He had only two serious relationships with women, neither ended in marriage.
Unfinished masturbation gives discomfort, but no serious illness.
married
no if you havent married eachother or had children, there just your boyfriend... its a not so serious relationship but holds seriousness within to maintain a healthy relationship
No, it is not a serious problem. You need to release your sexual tension by masturbation. You did find that it worked so you found your own answer.
No, he is not married, but he has a serious girlfriend named Kathryn Camsey.
no she wasnt married but she was in two serious relationships
You can do anything you like, but your boyfriend will get jealous. It also isn't recommended if you are having a serious relationship,engaged,married,or have children ,but even so it is your choice
He is not married, but is in a serious relationship with Lacey Franklin.
No. And if you think your ex is a sociopath, a term used way to loose these days, it is a serious diagnosis that only a doctor can make.
no she has never got married but has had very serious relationships