Prompt: They've been best mates for decades, and the chemistry has burned between them for nearly as long. But they were both married before they realised what those feelings meant, so they never acted on them. Until now.
Suggested Characters/Pairings: Ron/Harry
Theme/Tone: Desperate, smutty, first times
Additional Info: Up to you why they finally give in. Could be infidelity or that they're finally out of their respective marriages. Epilogue compliant.