Poll.
Would you reveal your deep dark past to your partner knowing
full well that it will destroy your current relationship with
him/her?
And I am not talking about some "when i was in primary school, I
stole my friend's pencil and pulled their hair" thing.
Really, really deep dark secret. 
Why do u hav so many questions abt love? Use ur "wait
20yrs for true love" theory to test on all these problems shld
help.
Seriously, I choose not to tell unless one ask. & If
im being asked, i wont lie but i wont go into details
either.
I wont lie, I only dun tell. Likewise, I dun usually prode
too deep into my exes' past r'ships UNLESS it concerns
with health. And if one has to lie in order to be in a good
r'ship, it's goin to be tough for tat person for as long as the
r'ship will last. One lie leads to another..in the end u need
more lies to cover tat one dark secret. No wonder it's called
"Dark Secret" - the more u cover it with other lies, the darker it
shall become.