Is He Honest or Deceptive?

Good evening madam. Please a lady friend of mine need your advice and that of your fans on this issue. She's a lady of 29 years old, Christian who is in love with a Muslim guy of 30 years old. The issue is the guy claimed to be traveling to see his sister every two weeks. Whenever the guy travels to see this so called sister of his, his character will change. He mostly switch off his phone, ignore her calls and talk to her like an ordinary friend. When he finally picks, claims he's busy and doesn't want her sister to know he's dating someone because she pays his tuition fee.
But whenever he's around her, he behaves normal. So she's doubting if he's really saying the truth or just deceiving her. Please she's confused cos she doesn't want a situation whereby he'll come back in future and say he's no longer interested in her.


Ordinarily I don't publish any mail from third party but I decided to publish this because I really don't understand what is confusing about spiritual compatibility. 
Islam is a religion of peace and in Islamic religion, they have their own codes and rules governing their way of worship. 
I won't bore you with the details but the basic principles of Islam concerning marriage is that you can marry up to four wives as long as you have the means to take care of them. So genuine Islamic wife understands this principle and doesn't go about fighting with her husband. 
Christianity on the other hand prescribes for one man, one wife for the rest of his life and total faithfulness to her. 
Every individual have the liberty to decide where they wish to worship just as every individual has the liberty to decide who to love, but you don't have such liberty to force your convictions on others. 
The first thing that every individual must consider even before accepting any relationship proposal is the spiritual compatibility, because it determines how every other aspect of your marriage or relationship will be. 
If as a Christian you so decide to date a Muslim brother, please settle it at the back of your mind that he has the freedom to marry as many ladies as he wishes to. If you don't appreciate the ideologies and the ways of worship of any particular church or religion, please terminate the relationship and go for a partner that shares the same spiritual or religious convictions with you. 
Coming to your friend, that man is already married, maybe his first or second wife, and that is why he doesn't want to be disturbed when he's incubating his wife. So he simply tells her some healthy and acceptable lies so that she will be happy. 
Again she needs to wake up from her dreams and ask herself what she truly wants for herself instead of deceiving herself in the name of being in love. 
Every individual owes himself the courtesy of choosing for himself who he or she wishes to surrender to or submit to spiritually and afterwards accept the terms and conditions of her decision.