having had the experience of sharing this 'lifestyle/fetish/need' with my ex wife of twenty years and my current wife of five years, i would have to agree that coming clean on this as early as possible in the relationship would be fairest option for all concerned.
as hard as it may be to open up to somebody else, let alone articulate in some way that makes any sense or meaning.( lord knows it's hard enough for myself to understand and accept), it needs to be done in the steps towards a truly honest and trusting relationship.
hindsight is a wonderful thing but i can see now that my marriage to my first wife was over well before i uttered my first stumbling words about my secret i had kept, believing that it may help save our marriage in some way. I would'nt say it was the final straw that broke it or the dealbreaker, but it just became another issue in the 'too hard basket'.
my confession led to many visits to a psychologist, at her insistance, even though i had readied myself with information for her. I was diagnosed with major depression which was a relief in a way because I was not functiontng very well at all and my 'regressive urges' were nearly out of control.
the marriage ended but we have kept an amicable relationship, with her even asking me if I had told my new partner about my stuff as she put it.
my current partner (wife) knew of my need, to some extent at least, from very early days of the relationship.
her limited involvement in bdsm made it easier to broach the subject but trying to explain the nitty gritty of it all has still been chalenging and embarresing. incorporating it into a balanced life style amongst all the other dynamics within the relationship remains a work in progress and a very enjoyable one at that.