Okay, I'll try to explain why a kiss on the forehead is not a good idea in the situation we're talking about. The problem with that kind of kiss is that it sends mixed signals and it's very easy to misinterpret. Especially if that's the only physical contact between two people and especially if it happens before the nature of the relationship is clearly defined. Typically, it suggests protection, care, affection, but without any sexual intentions, but it can mean a lot of other things and that's why it can be so confusing.