Cabaceo by proxy

I am learning all the time about the cabaceo (for the normal reader, rather than the tango obsessive, this is the invitation to dance with the eyes)
In England, when this is possible it has been for me a gentle system. I look and catch the gaze of a follower, slowly we appreciate that there is an invitation, there is a hopeful nod from me and a response and we both sigh with relief that it has worked, stand up and dance.
The dynamics are different here. Often the follower initiates with a gaze like a beam of ultra-violet radiation. To fail to heed this will cause skin damage. To deliberately ignore .....well, I cannot say as I have not dared! The mere fact that there is no direct line of sight is not an obstacle. The woman may lean out of her seat with the upper half of her body horizontal as her penetrative gaze has me leaping to my feet. Indeed if there is another person alongside, who is in the line of sight, then he is cabaceo'd and with shakes of the head the message transferred to me - cabaceo by proxy!