Loan sharking: Giving unsolicited help to the chosen victim and anticipating they'll feel obliged to extend some reciprocal openness in return.
The unsolicited promise: A promise to do (or not do) something when no such promise is asked for; this usually means that such a promise will be broken. For example: an unsolicited, "I promise I'll leave you alone after this," usually means the chosen victim will not be left alone. Similarly, an unsolicited "I promise I won't hurt you" usually means the person intends to hurt their chosen victim.