I don't think theft is the primary concern.

Mine is that the two of you both manipulated and used each other to get what you wanted. She wanted drugs or alcohol. You enjoyed a chance to rummage through people's things.

I was an inmate here. I know how easy it is to get your hands on contraband in port. How simple it is to talk certain wardens into letting you off the ship unsupervised, or even giving you spending money. You had plenty of options besides breaking into cabins.

Won't break into cabins, or won't use each other for your own ends?

Because I know from experience that the second is much harder to promise than the first.

At home.

Though I notice that was a question, not an answer.

If I tell you more about this, will you use it as ammunition to prove that my relationship was nothing like yours and Natalie's, and disregard any similarities that do exist? [Her main hesitation, here! She's not entirely against talking about Signy, especially now that revenge is so close she can practically taste it.]