But how do they know

I have been cruising before or at the adult booths and made signals or gestures by licking my lips, pushing my cheeks put with my tongue, hand motion of jerking, dressed up or similar to let someone know I was interested. But this week after an encounter I wonder how do they know with no cues!!! I was traveling with work last week and decided to stop into an adult store on the way back next to the interstate. I had never been here before so I walked around browsing straight movies and some sex toys as I watched the traffic in and out of the arcade area. I was looking down at the back of a DVD when the door chimed. I glanced up to see a guy mid forties walk in and go straight to the arcade. I waited 5 or 6 minutes then walked into the arcade I went into the theater area and looked around it was empty but as I started to leave I noticed someone standing in the corner in an area just behind the exit/entrance. As I walked towards the door I noticed it was the same guy that walked in when I was almost at the door he said come and motioned for me. I stopped at the door and he said it again just loud enough I could hear it over the gangbang moans on theater screen. I stepped towards him and ge instantly pulled put his hard cock and put his hands on my shoulders applying slight pressure downward. With the light of the screen I was now squatting in the floor mouth to cock with a nice 6.5 inch fat cock and huge balls. But how did he know what I would do and what I was wanting with no cues. Regardless I went to work I was so horny and my mouth salivating it was loud sounds or slurping moist pumping until he grabbed my head and feed me a hug load of hot cum.