Have you spoken to the landlord about this? It sounds like you have a reasonable case not to allow others to have your key. — Underverse 57 secs ago

@sphennings - "If not that's cool" can be misinterpreted as a lack of interest if in the preceding sentence they are asking someone out because what behaviour expresses counts much more than logic in written texts. And often when people are in high emotions, a way to deal with high emotions is t verbally minimise them, to the point that you see a contrast between the verbal statement and the non verbal communication of gestures, individual self-expression to communicate desire and care. And contrast is something the listener can perceive as weird, as a threat, even if there is nothing harmful. — user305883 52 secs ago