1(a) because reality is usually less scary than whatever I'm otherwise imagining they're doing, 1(b) sometimes it is actually fun, in a sort of voyeuristic sense, as long as the OSO is ok with that.

2(a) anyone I date knows that I will keep details of dates confidential *if asked*, otherwise I will answer direct questions or give synopses to other partners with an interest.

3 My own strong preference is for openness... if a partner is hiding things from me involving their other SOs, that immediately triggers my safety (physical or emotional) concerns.