I spent many years working the soundboard at a couple of churches. I worked with one young man who had a great voice, but he was worried about over powering everyone else. I learned that if he could hear himself in the monitor he would reduce his volume. If I turned his voice up to compensate, he would get even softer. I had to take his voice out of the monitor, while leaving it in the house speakers.
What does this have to do with sex? I discovered when he tried to sing too softly the quality of his voice was reduced. When he was belting it out, he was great; when he was worried he was too loud he sounded bad. I have come to realise sex is much the same way: when you hold back too much you reduce quality – and pleasure.
While this is true for men, it is usually a far bigger issue for women. The whole “good girls don’t _____” mentality is alive and well, and it causes women to hold back. Women are concerned about things like “wanting it too much”, “enjoying it too much”, or “making too much noise”. They’re worried their God given desires are wrong, or kinky, or not appropriate for a godly woman. I know this sounds odd to most men, but it’s common among women.
Be aware your wife may have such fears. If you see indications she’s struggling this way, say things to reassure her. Express enjoyment of her pleasure, and gently encourage her to let go more and more. Ask her what she wants more of, what she would like done differently, and what she would like to try. Don’t do too much at once, just stay with it.
By the way, the best time to help her stretch sexually is after she is well aroused, but before she is so close to climax she can’t think straight. Arousal will reduce her inhibitions, making it easier for her to be a bit daring. Again, don’t try to go too far at once; you don’t want her to do something she will feel bad about later.