Your leo has a prolapse and needs to be taken to the vet ASAP. Whether it's rectal or hemipenile prolapse, I can't tell. Probably hemipenile, but either way it's very dangerous and an infection can cause your leo to die. Please take it to the vet immediately so this can be treated. There's no way you can fix this at home. A licensed and trained veterinarian needs to help fix this little guy.
There's definitely something going on. I would try a good 10-20 minute soak in a sealed tupperware with 1/2 inch of 95 degree water. If whatever it is doesn't slough off or go back to where it's supposed to I would get him to a vet ASAP just to make all is okay.
Soak him in hot water with honey or sugar soaked in it. That has reversed a few minor prolapses in the past for me, but if it doesnt retract get him to the vet