"Is it true that sex gets better with time?"
If the relationship is growing deeper, kinder and continues to be invested in, then yes, sex is likely to get better too. As you grow in confidence in your own skin, you can experience the freedom of sexual abandonment and recognise the value of playfulness. However, this requires that you retain the role of sex in your relationship as an ongoing pleasure and bonding experience.
"Are you still a good wife if you say no? How many times can you get away with this answer?"
Of course, both partners must be free to say no when they do not want to have sex. No balanced person wants to have sex all the time. No partner has the right to insist on sex from their other half. Wives have been protected by the law through the offence of rape since the case of R v R in 1992, where the House of Lords made it clear that a husband can be convicted of raping his wife.
However, it is also not healthy if we are always orientated towards wanting to say no. That is indicative of angst within ourselves and/or within our marriage. Such drivers need to be listened to and rewired. Each of us has responsibility for our sexual responses, and God would have us grow into all that he has created sex to be as a pleasure gift to bond the love of marriage. There are no ‘shoulds’, because the seasons have their own wisdom and inevitability. As it says in Ecclesiastes 3:1-5: ‘There is a time for everything…a time to heal…a time to embrace and a time to refrain’. There are times of sickness. But the journey of God is always towards life and wholeness.
If you are struggling with more often wanting to say no, I suggest you seize the initiative yourself, rather than waiting for your partner to initiate only to find you’re not in the mood. Warm yourself up so you are prepared for physical closeness. Get yourself in the best place you can be mentally, emotionally and physically, and then take the lead. You may not feel turned on to start with, but if you teach your partner how to touch you in a way you can enjoy, and allow yourself to respond to their touch rather than dismissing it mentally and shutting down, then the turned-on feelings can emerge as you go.
"I have been married for a long time (23 years) and have had 10 years without sex. I want to resume a sexual relationship where I have previously punished him emotionally by saying no. How do I let him know I want it back again – no sexy lingerie, please."
I would be honest and tell him. This is about more than resuming sex. It’s about stopping playing games, stopping punishing him, and opening a new order of things where there is freedom of love and honesty in your bodies. Be straightforward. Tell him what you are thinking, how you are feeling, and how you would like it to be. Tell him what you want to bring to an end, and what you would like to start. Hear him, too. Find mutuality in an idea of what you both want; then make it practical by deciding how you would both find it easiest to move this forward, bearing in mind it is going to be a journey, not an instantaneous experience.
When you have done everything with the maximum maturity possible, then get down on your knees and commit yourselves to God in prayer, asking him to inspire and strengthen you in this next chapter of your marriage.