The same happens to me. The tongue doesn’t do anything at all for me. All of my girlfriends seemed to like it though. This is contrary to what the article says, but I understand that every person is a world… which is why looking at kissing scientifically makes little sense to me. Just try things and see what works for both of you (and don’t neglect doing things that don’t work for you if they seem to work for the other person, of course)