"I was due to offer peace offerings; today I have paid my vows"
Solomon includes, in this picture of adultery, some of the very convincing arguments that the adulteress makes to try and convince this man that she truly loves him.
This is the Hebrew word shelem, which means a specific offering made in the Old Testament called a peace offering. Leviticus 7:12-25 describes this offering. It was to be offered at the altar and partially consumed with the priests, but the rest of the offering was to be consumed at home with one’s family as a joyful celebration of love for the Lord and one another. It had to be consumed in the day that the offering was made.
In this way, the adulteress convinces her target that she truly loves him. She basically says that I cannot think of anyone that I would rather be with than you. You bring me joy. I must consume this offering with those who I truly love and I pick you. My husband is out of town but you are the one I truly love, and we can share this feast tonight together.
She creates a false time deadline which the young man thinking of committing adultery is up against. There is a sense that all this food will go to waste, and that she has created an artificial deadline to convince him to be with her. Men also do this in adulterous situations when they say things like "it’s now or never" or "if you really love me then…"She has completely blown off the nature of the offering to God. The whole peace offering at the temple is just an empty ritual with a lot of meat left over for an intimate party at home.
There is a warped way that those involved in adultery also begin to think. They can begin to thank God for the person they are committing adultery with. They are so momentarily happy with this person and their illicit love that they can mistakenly attribute this person as a gift from God. So, she may be making a peace offering to celebrate with God that in her mind He has given her a man who truly loves her. And the leftover food will allow her to continue her celebration with her new love. So, for her this peace offering is perfect as a celebration of and indulgence in her sin.
I have heard this kind of twisted logic coming from those involved in sexual sin. They do not understand that God is not the author of sin. Some people have embraced the false notion that God wants them to be happy all the time. Therefore, if something makes you happy, it must be from God. Realize He is not going to help you sin. He is not providing ways for you to sin. It is the Devil who is helping you do what is clearly immoral. It is your flesh that is racing to help you find ways to be selfish. It is the world system around you that wants you to find joy in immorality. It is not God. This will become painfully obvious when the consequences begin to show up in your life. Then the "god" who supplied you with the gifts of sin will fail you. You will be left facing the real God and His real opinion and judgment about what you did.
Just because it is easy to sin, do not take that as the will of God. It is not God's will that you sin.