A male masturbatory technique where the man interlocks his fingers, pinky to pointer, so the knuckles are touching. He then places his penis in between the "spider legs" and uses the grip to pleasure himself. This grip often involves the use of the thumbs on the head of the penis. The use of thumbs is often referred to as "Chelin" in reference to the name of a spiders mouth parts.
I'm not a big fan of the stranger, I think the spider grip feels way better.
My gf spider gripped me last night and it was amazing. She even chelied it!