Hilchos Issurei Mizbeiach 4:10

Let’s say that one person tells another, “This item is for you. In exchange for it, please have your Canaanite woman servant spend the night with my Jewish man servant.” This is considered the wages of prostitution, but only if Jewish man servant doesn’t have a wife and children. If he has a wife and children, he is permitted to be with a Canaanite woman servant, as we will discuss IY”H in Hilchos Avadim. The same rule applies if someone tells a prostitute, “This item is for you. In exchange for it, please have relations with person X, who is Jewish.” Such a gift counts as the wages of prostitution.

Hilchos Issurei Mizbeiach 4:11

If someone made a deal to pay a prostitute one sheep but he ended up giving her many they are all considered the wages of prostitution and are prohibited for the altar. This is so even if he gave her 1,000 sheep. If he gave her a gift but was not intimate with her, but instead he told her to hang on to that item in anticipation of some future “transaction,” the item in question becomes prohibited for the altar when he actually is intimate with her. If she offered it before they engaged in relations, it is accepted; if she was obligated to bring an offering, it fulfills her obligation. This is the case so long as when he gave her the item, he told her that she acquires ownership of it immediately. If he didn’t specify, the item not accepted because one can’t offer something that doesn’t belong to them.