If as you say you are a married couple, then it is fine for you to speak of sexual intimacy with your spouse on phone or private chat sessions. Neither of you should have no inhibition in such matters between both of you.
Islam celebrates sexuality. The Prophet (peace be upon him) said, "You stand to gain spiritual blessings in establishing intimacy with your spouses. Upon hearing this, the companions asked, “How can we be rewarded in fulfilling our physical desires? He said, “Even as you will be punished for seeking sexual fulfillment outside the fold of marriage, Allah will reward if you seek the same lawfully (as married couples).”
If your wife has no knowledge of such matters, it is important for her to get educated on such crucial issues. Here are two good books I would recommend for both of you to read together. The first one would be a great resource to discuss such matters. So get them and try to educate yourself and your spouse.
Here are the two books:
The Muslim Marriage Guide Book by Ruqaiyyah Waris Maqsood
Blissful Marriage: A Practical Islamic Guide by Ekram Beshir.
I pray to Allah to bless your marriage and grant you joy in your relationship.