The marriage bed must be a place of mutuality -the husband seeking to satisfy his wife, the wife seeking to satisfy her husband. Marriage is a decision to serve the other , whether in bed or out. Abstaining from sex is permissible for a period of time if you both agree to it, and if it's for the purposes of prayer and fasting-but only for such times. Then come back together again. There's more to sex than mere skin on skin.
Sex is as much spiritual mystery as physical fact.
Don't you see that you can't live however you please, squandering what God paid such a high price for let people see God in and through your body .