I once participated in a prayer group with a fellow who cussed when he prayed. My friend had not been a believer for long and he had a lifelong habit of cussing. By the time I knew him, he had cleaned up most of his really bad words. He no longer talked about people's mother or intimate sex acts in his slang, but most of the four letter words were still there. And when his prayers would get into high gear and Spirit started flowing, out would flow those four letter words.
It used me make me laugh. To be honest about it, I don't think the Creator was embarrassed at all. According to the Good Book, the Holy One sees our hearts. My friend's tongue may not have been pure, but his heart was.