I stopped for two years when I got into a long term relationship - combination of great sex and fear of getting caught/giving her an STD (not that I've had STDs as far as I know - I get tested every year and so far am clean).
In the third year we did the long distance thing and she gave me permission to use AMPs to deal with the build up of bodily fluids, after which we went on a break - so yeah, I was fucking around then because I knew what 'on a break' meant.
Anyway, since breaking up with her I have had a few FWBs or hook ups but a combination of lack of interest and (more realistically) a really spotty employment record since moving back to Britain has basically seen me consciously decide to stay single and keep banging pros.
Would I quit again in the future? Well that is a hard one to be honest because when I quit before I was very young and naive, and not very sexually experienced. Now I'm crusty and like hopping from one vagina to the next, and hold relationships in less esteem. I suppose I would quit if I had a few years of career stability behind me and was getting towards the end of my thirties. But my fantasy is to meet a middle-aged bisexual lady who wants to have threesomes with me and a steady stream of escorts, so it may take a while
In all seriousness I think sex loses its importance as you get older. A lot of married guys who use escorts are reacting against having dead bedrooms in their prime shagging years when they were trying to make things work with the missus, and now feel like they have lost time to make up for. I would be in the opposite situation so we'd see.