Trickle Truth - it's when the BS gets information piecemeal.
EX: WS says there was no sex. Two weeks later, there was some 'making out and groping' but no sex. Three weeks after that there was oral sex, but no 'sex sex'. One more week - they had sex once. Another 4 days - they had sex 7 times.
Trickle truth - very harmful to R