Responses
Um, no.
She's older than she looks. Look at the description. Office lady is reborn, so 30+ is her mental age, 15 is just the physical one. And I do believe she was about 17 when they married. Plus, the first few chapters give background on both, while the rest of it comes later.
So while I agree with the above "TED" talk to a point, it does not fit the story.

Like, why would I be perfectly fine with a 15-yr old and a thousand year old dragon, but she's 15 and he's 26 and it's just uncomfortable.
PSA: To any young teens on this app, that age gap is not normal, age is NOT just a number, and he does NOT think you are mature for your age. If girls his age are not with him, there is a reason. It's not because they don't understand him, it is that they DO. It's not some forbidden romance, it's an illegal romance for a reason. If an older guy tries to date you while you are a teen, it is because you havent had enough experience to recognize all his red flags. Thank you for coming to my TED talk.