1. It starts with Harry being attacked by his Uncle. Vernon pours some chemical in Harry's eyes and then leaves him in a forest (I think?) for dead. Snape is riding his horse when he comes across Harry and takes him back to Snape Manor to heal him. Harry recognizes Snape but because of his injuries Snape doesn't recognize him.
2. Harry and Snape are both stuck in a safe house. Snape convinces Harry to practice his potions and brew a cleaning potion that is highly poisonous. Harry finds out that Snape can't use his magic and is attempting to kill himself. Harry stops him and they start a relationship. Pretty sure it was a oneshot.
3. Harry plays stips pocker (or some stripping game) against Snape, Sirius, Lucius, and Remus and wins. His reward is that he gets to spend a night with each of them and they have to do what ever he said. Heavy slash and I think it was 5 chapters.