What does it mean when guys always throw themselves onto you immediately when you meet them for a date?

Anonymous

I’ve been dating (for the first time) and I have noticed that when I speak to them on the phone and text them - no red flags. But as soon as we meet face to face and they see me; I can immediately see that a switch inside of them happens and their whole persona changes and they immediately start throwing themselves at me. From physically groping me as we are greeting each other to kissing me within minutes of introducing each other. I’m very shy, quiet and introverted by nature and it takes a long time for me to get comfortable and warmed up. I don’t throw myself at them or present my body in a specific way to invite such behaviour. I’m fully aware that they’re attracted to me and vice versa or we wouldn’t be meeting. But this is the first date and I tell them before hand to not to do anything and how my only intention right now is to get to know them. how do I stop them from throwing themselves at me or at least give me a brief perspective to why this always happens?

Updates
5 mo
I always meet them in public places.
What does it mean when guys always throw themselves onto you immediately when you meet them for a date?
6 Opinion