A connection can happen between people without meeting. This has been since even before the internet.
Example of way back before the internet: Men and women have met through the prison pen pal thing or maybe not even prison but from one country to another. Just being "pen pals" - They met only on pen and paper. The exchange of writing back and forth and getting to know each other, bonding, connecting still occurs. Feelings happen, even love. With that the lining to hear from them.... missing them is natural.
And it is the exact same thing virtually. You don't have to meet face to face in person. You don't have to have sex.
In fact, I feel that you can develop even stronger connections this way because MORE is put in than when face to face knowing each other.
I have loved in real life and in the online world. The intensity of the feelings weren't any less.