I think that Cossette needs to realise that Steve has some very odd ex co-workers and that sometimes they are very alarming ex co-workers (or, in Tortura's case, ex elite enemy agents)! For most relationships, Tortura 'dropping in' would be a kiss of death. With Cossette, I'm really not sure but I suspect that she'd take it as an occupational hazard.
What I think Tortura needs to understand is that sometimes relationships mean compromise. She's already told Steve before that she kind of wants out of the game. As bizarre as settling down to write one's autobiography as a series of stories for ages 5-8 years might seem for an ex super-spy, something tells me that, in the end, it would make her happy. Sometimes, getting 'bored' is better than the alternative.