From a young age I decided not to have sex before marriage, and I have tried my best to make it until now. I am 24 years old. My fiance is 25. We decided to get married in six months. Our families know that and he has put an engagement ring on my finger already.
However, sometimes when we're together he wants to touch me and kiss me. Is it a sin for unmarried but engaged couples? Sometimes he asks for sex, but I always refuse.
My other question is this: he went to visit his family who are far away. We don't visit each other (we study in a foreign country and he is coming back to school in a month), but he is always asking me to talk to him on Skype with both of us naked. Then last week he asked me if I will let us have sex when he comes back. I refused as usual, and I told him to wait if he really loves me, but he was very angry and said that I don't trust him anymore. Our communication is not good as before, his smile has gone, he's not happy like he used to be, now I don't know what to do. I am trying to tell him that we have to wait until marriage, but he is also says: "I told your family and mine, I put a ring on your finger, and I committed to marry you, if we do this, it won't be a sin because you're almost my wife. I love you. I promised not to leave your side and explain that the sin is when someone is having sex with someone who is not his fiance."
I wanted to ask my mum for advice, but she's not answering the phone, so I'm here asking for your help. I need to know the truth behind this. If it is a sin, I won't do it. I don't want these three things: to lose Jesus Christ as my Savior, disobey my parents who taught me to not have sex before marriage, and have a misunderstanding between me and my fiance.
Please help me.
Your finace is wrong. Fornication is when two unmarried people have sex with each other. You and he are not married. All you have is a firm plan to get married, but that isn't the same as being married. "Marriage is honorable among all, and the bed undefiled; but fornicators and adulterers God will judge" (Hebrews 13:4). Without the vows of marriage, you or he can call off the engagement at any time with no consequences other than broken hearts.
The reason your fiance is pushing for sex now is that he is being selfish. He is not thinking about what is in your best interest (or his for that matter). Love "does not behave rudely, does not seek its own, is not provoked, thinks no evil" (I Corinthians 13:5); yet, despite his protests, he is demonstrating that he doesn't fully love you.
He claims you don't trust him. Frankly, I don't trust him. He is not acting as a Christian ought to act.
If you understand that fornication is wrong, then you need to realize that the things leading up to fornication are equally wrong. See: Is it OK to be sexual with someone you will marry soon?
There is a strong possibility that he will call off the wedding because you are remaining faithful to the Lord. While it may seem horrible, if such a thing happens, it will be better than being married to a man who has no respect for God. Though this is written to married couples, I think it equally applies in situations like yours: "But if the unbeliever departs, let him depart; a brother or a sister is not under bondage in such cases. But God has called us to peace" (I Corinthians 7:15). You have no obligation to keep an engagement going with a man who is demanding that you sin with him. Do not compromise your faith to satisfy his desire for sin.
You may have to consider ending this engagement since he is demonstrating that he is not a faithful Christian and so will not make a good husband.