If Harry were to stop and think about it, Remus is sure he would realise James was not Lily's first and only boyfriend. If that day comes, he's prepared to answer the boy's questions.

It was only a teenage flirtation, really, nothing very serious. And when, aged seventeen, Remus realised James was in love, and Lily was too, he stepped aside readily and let them find each other.

He thought James could give her a better life. He was rich, and more importantly, he wasn't a werewolf.

Merlin, but Remus regrets that now. Even life with a werewolf would have been better than no life at all.