Probably the most common understanding of chastity is "sexually pure." I had primarily connected this definition with virginity, and it certainly does encompass that. But staying sexually pure also relates to marriage. A companion definition to "sexually pure" in Strong's Concordance is "staying within the marriage vows."
For married women and unmarried women alike, this means guarding our minds and hearts. It's all too easy to let our minds drift to romantic daydreams in which we are appreciated as we feel we ought to be and told how wonderful we are. This is especially tempting when our marriages may feel dull and dry, or when we feel unappreciated and not loved the way we'd like to be. Whether Mr. Romance in your daydreams has a face or is faceless, it makes no difference. These daydreams are lies and are not "staying within the marriage vows" because we are not learning to love, be grateful for, and appreciate the husband God has given to us.
If you are unmarried, you may think these kinds of daydreams are harmless. Let me assure you they are not. You are building mental and emotional habits into your life that don't suddenly cease the day you get married. I know—because the Lord had to break me of this early on in marriage. You may argue, "But my daydreams aren't sexual; they are just romantic. So there's nothing impure about them." But those romantic daydreams can set our husbands up for failure and set you up to be discontent and dissatisfied. Rather than being grateful for the day-in, day-out things that our husbands do for us, we find them never measuring up to our romantic expectations. With these mental, unrealistic clouds we are not "staying within the marriage vows."
We are to stay "pure in thought, action, and dress"—another Strong's definition. You may have to curb what you read and what movies you watch. If they start romantic daydreams spinning in your head, then stop reading/watching that stuff. Do you realize that most romance novels are written by women? That means that women are putting into the mouths and actions of their characters what they know other women would like to hear or have done for them. Generally, it's not very realistic and not the way a real man thinks and responds. Let your man be a man. Appreciate his manliness—even if it means he's not the most romantic person on the planet. Don't try to feminize him, or try to make him like yourself, or depreciate him because he doesn't think like you. No real man walked out of a romance novel.
Our thoughts need to stay pure, but so also do our actions. We must never be flirtatious or seductive, trying to draw other men's attention to us. Paul exhorted Timothy to "treat older men as fathers, younger men as brothers, older women as mothers, and younger women as sisters, with all purity." This is excellent advice not just for young men but for us as well. If we treat other men as brothers or fathers, depending on our age and their age, we help to create an atmosphere of ease and friendship. We are comfortable to be around, but we are also safe. As chaste women, we conduct ourselves with dignity and grace, with decorum and respect. This requires a certain reserve that speaks of being set apart for the Lord, so there can be no impure motives and implications attached to our conduct.
This kind of chastity is tightly linked to learning to be discreet—the word we looked at in the November Titus 2 blogs. This kind of chastity also lends itself to loving our husbands more and more, using our mental energy to think of ways we can appreciate and serve them more fully. Let chastity be the springboard for staying pure inside the bounds of marriage. If you're single, keep your mind and heart clean, warding off temptations to either sexual involvement or romantic fantasies and fixing your eyes on Christ and His purposes for you during this time of your life. Singleness is the best time to build good mental and spiritual habits into your life. If you're married, set your mind and heart on the husband God has given you. Be chaste in heart and mind, in word and deed. It would be a helpful and wise habit to periodically re-read what you promised to your husband on the day of your wedding; we need the reminder of what it means to "stay within the vows of marriage."