Sex is not suppose to be a chore in marriage. It is supposed to be something wonderful between two people that love each other. That is one of the most important ways a couple shows their love for each other. As soon as you think it is becoming a chore and not something you are enjoying you are supposed to look for ways to make it enjoyable for you and your spouse.
Kingozzy, I agree with you that sometimes people just lose the fire and that sex is the first thing to go but there are ways to get that fire going again. A nice dinner, a movie, taking walks together and just enjoying time together. Like me and my husband make one day a week date night (sometimes it last all weekend
)and we do things we enjoy doing together and that keeps our relationship strong and the fire and excitement in our marriage.