People engage in sexual activities for many different reasons and it can be done out of sympathy or for pity. People have sex when they get aroused, but some others may start having sex and then they feel aroused. Some women feel pressured into having mercy sex with their guy for reasons that have nothing to do with desire or love. These women are not really DTF, but they just give in anyway and have sex with their partner, even when they are not in the mood. Most women are not doing this out of desperation or fear of rejection, they are just doing it as a courtesy to be polite, because they feel sorry for their partner. They may think that they are helping him work through some of his problems by engaging in promiscuous sex without sharing intimacy and this is usually just a quickie, so it is convenient for both of them and it is no big deal. Mercy sex can be a good thing for a relationship, if it is done without coercion and you are not becoming a trophy just to be had, because when marital duties are neglected the whole relationship may suffer.
Many women lose sexual desire when they are in a long-term relationship or when they are married with kids and this makes them feel that sex is just a routine. Mercy sex is done when you don’t really feel like having sex, or you don’t want to hurt your partner’s feelings, or when your partner is feeling pathetic about themselves and you have sex out of some type of some obligation that you feel, so you try to appease your partner’s needs. It is done because it will take less time to just do it and it’s less trouble to get it over than to argue about it and you know that when you give him the mercy sex, that will shut him up. Mercy sex may also be triggered by some type of guilt, where you end up being manipulated and taken advantage of because of your sensitive vulnerability. When couples get married, the woman usually hopes that her man will change over time and the man hopes that his wife will never change, because the sex is exciting and pleasurable, but change is inevitable and sexless marriage are experienced by many long-term couples.
Sexual drive is often independent of that part of our mind that judges what is deemed to be appropriate. There is also revenge sex or grudge sex where some girls want to make their boyfriend jealous, or after a relationship is over (sex with the ex) when you still have sex with each other because it’s more convenient that going out in the world and taking your chances with a stranger. In a perfect world sex would only happen out of genuine respect, love and mutual attraction and it would never be about taking advantage of someone who is in a fragile state just to get off and have your physical needs satisfied.