Can I trust my fiance because she is online up to 1 am on Whatsup? What can I do? Can I ask her whom with you are chatting?

I'd say sit down with them calmy and ask if they are hiding something or if they needed to tell you something. If she doesn't say anything or tries to change the subject, let them know that it's okay and that you'd still love her even if it is what you think it is. Make sure they know that they are still loved by you so they could come to you and tell the truth. I hoped this helped a lot and keep me posted on what happens between you and your fiance. MAke sure to not raise your voice.

I think it is important to have an open channel of communication. Considering you wish to eventually marry this person, it is important to establish that beforehand. I think the best you can do is bring it up and talk about it openly. Do not accuse her or yell at her about what she is doing; as this may put her on the defensive and make her clam up or believe you do not trust her. It is important to establish trust and an open communicative channel between the two of you. The best way to do this is through attitude and general tone. I would avoid bringing it up in a stressful environment, as well. If she has just gotten home from work or school, she may not want to have this discussion. It is best to leave it for when you are both in a decent mindset, where you're willing and open to talk about things. If she is not open and becomes secretive, it may mean that something is up- to which you will have to determine if that type of behavior is acceptable within your own life. Every person deserves someone whom they can trust and rely on to be honest about their every action. Do not forget that! If she is honest and it turns out to be something you were hoping against; you will have to determine whether the relationship is worth salvaging. That may mean couples therapy, postponing the wedding, or simply ending the relationship. In the end, just try talking to her! It may be difficult, but at least you'll have your answer. I hope everything works out!