I've had quite a few...most just approach late at night. You can usually tell if they're interested by the conversation, the looks, or hesitation to walk away after you've given them the change or whatever they've asked for.
The first guy I met was near a homeless area in my city. I was sitting in my car smoking (purposely in the area, cruising) and he came up and asked if I wanted to hang. Went to my apartment, sucked him and watched him jerk off while watching porn.
The second guy, I saw walking around late at night. He was a little mentally unstable, but me being horny, found it hot. He walked past my car and I just came out and asked him if he wanted to jerk off. He hopped in and we did, then asked if he wanted to go somewhere more private, he said yes. I took him to buy his stuff, then we went to my apartment and had fun all night. Unfortunately, he couldn't keep it up, so we just messed around.
Third guy, was middle of the day. I was walking into the store, he came up and asked for change, I gave it to him, then he kinda hesitated and gave me that look. I was parked nearby after I came out of the store, he was pacing up and down the street. He then came up to my car, asked me "what's up," then I told him I'm just hanging and asked if he wanted to hang. Took him back to my place, asked him if needed anything, clothing wise, then jerked him off (he came quickly), then gave him head, he came again and took him back. Saw him a couple weeks later and he just came up to my car and got in. Went back to my place, and messed around. I asked him to lay on me and grind, and he immediately laid down and stuck it in. Was amazing. Dropped him off afterwards and haven't seen him since. Been looking though.
The last was at an intersection asking for change, just came up and asked me for change. I told him nah. Then he came out and asked If I was single. I said yea, and he asked If was trying to "chill" so I said yeah. He hoped in and we went to a secluded spot and jacked off together.
All of these were fun experiences. I don't feel like I"preyed" on them because they mostly asked me.
Feel free to DM if you want to chat.