(Background info: There are 3 categories of male Bluegill Sunfish; the most desired by females are parental males who build nests, and tend to eggs while they develop and hatch. Then there are sneaker males who are smaller and less aggressive males. Lastly there are satellite males, who resemble female fish in size and color.)
"... Sneaker males lurk in hiding places near a parental male and zip into their territory while the parental male and female are spawning. Sneakers then shed their sperm over the eggs and swim away, the whole process taking less than 10 seconds, cuckholding the Parental male..."
"A third male morph, Satellite males, also exist. Satellite males tend to look like females. Disguised as such, they position themselves between a spawning pair. If the Parental male is duped into believing the Satellite is another female, he will attempt to mate with both "females" (the actual female, and the imposter male), at which point, the Satellite male will shed his sperm over the eggs, again, cuckholding the Parental male."
I realize that to put humans in the place of these animals is a bit disturbed, but it makes my class more entertaining, so there.