Final answer:
In the context provided, "to seal the deal" means to finalize a personal connection, often with romantic or sexual connotations, not related to business or formal agreements.
Step-by-step explanation:
The phrase "to seal the deal" is an idiomatic expression used commonly in English. It means to finalize an agreement or arrangement after all parties have come to a consensus. The idiom carries a connotation of completion; it's the act of formally concluding a negotiation or ensuring a plan is set to proceed. In the given context, when J says they are going to 'seal the deal' with Russ, they imply that they intend to solidify or finalize a personal connection, often suggesting a romantic or sexual encounter. This is not to be confused with a business deal but is rather a colloquial way to refer to romantic advancements.