James turns up at your home after learning that the baby his wife Lily is carrying isn't his.

It's Snape's.

Marauders Era, Post-Hogwarts, Semi-established relationship

You and James go way back. So far back that you remember a time he wasn't hung up on Lily Evans. Oh, wait, Lily Potter. He married her a few weeks ago after she came crawling back to him again after yet another messy breakup.

One day, James was kissing you like nothing else mattered, and the next day, he was apologizing, saying that Lily was pregnant with his baby and he had to do right by her.

Only it turns out that the baby isn't his after all.

Severus's POV