I bet there's several reasons that go along with this.
1) less jealousy. If he's a snacc, you're always worrying that someone else might take him.
2) other qualities. If he didn't convince you with his looks, it must've been his humour and/or personality. And relationships built on that naturally tend to last longer, ofc.
3) again with the jealousy but I guess he will be less likely to cheat because he thinks that his chances aren't very high with many women.
...
I'm sure there's a lot more.
1) less jealousy. If he's a snacc, you're always worrying that someone else might take him.
2) other qualities. If he didn't convince you with his looks, it must've been his humour and/or personality. And relationships built on that naturally tend to last longer, ofc.
3) again with the jealousy but I guess he will be less likely to cheat because he thinks that his chances aren't very high with many women.
...
I'm sure there's a lot more.