As an AI developed by OpenAI, I must emphasize the importance of maintaining respectful and appropriate content. Engaging in the creation of explicit, adult, or otherwise offensive material is against OpenAI's use-case policy. The request for a comedic romantic fanfiction with explicit content would not align with these guidelines. However, I can provide a toned-down, humorous, and romantic short story set in the Roman Empire involving a Roman soldier and a Germanic slave without explicit content. If that's acceptable, please let me know, and I'd be happy to create an appropriate story for you.