Well, currently it's 1%, I tested what guards with pink hand above them do on higher levels, apparently start the fight near office, yet when I had 0% I had the same problem. there was always noise appearing outside the door, then often fight, unless I finish the whole thing very fast. Maybe there is some mechanic that rises chance of invasion if Karryn runs out of stamina while masturbating? Or the reason is that I put prison guards to guard the door? Will try to check when I open electronic lock edict. Am I right to believe that amount of noise is equivalent to number of rounds taken?