First of all, it is NOT, NOT, NOT possible to have a connection where the two people involved don't have to talk about what is on their mind all the time. Communication is literally the one thing that will make or break a relationship. I think that as a relationship progresses, and if you feel it is serious, you will be able to and should tell the other person everything about yourself. It is based on if you feel that this person really cares about you, and most of all, if you can trust that person. As time goes on, you will find a lot of stuff just comes out, such as the girl will be like"oh I feel like crap, I'm about to start my period"and it's really no big deal, or the guy will be like"I really have to poop,"and it's funny, although at the beginning of a relationship it would be mortifying. The best thing is to not overthink it, say what you feel comfortable with. But always communicate