Trope
Forced Proximity
Forced Proximity keeps two people in the same room because a contract, a debt, or a threat will not let either one leave.
The heat of the trope is the locked room. In Void Pact the room is the card table, then the sweep.
Void Pact: The Dealer's Debt
Kane and Leo. Dark MM Romance, Mafia, Heat 4. Enemies to Lovers, Forced Proximity, and a debt contract. The free trial is chapters 1–3.