Oh I've heard of this. It means the activity of putting one's face between a woman's breasts, and rocking turning one's head rapidly from side to side while making a noise like a motorboat(I found this on the internet). But I guess it can also work down there too reply
Y'all motorboating is ''The act of pushing one's face in between two ample breasts, and rocking one's head side to side very rapidly while making a vigorous, lip-vibrating "brrr" sound.”
Edit: Um I'll update I guess reply