Then just treat it normal. The more you try to justify that it's not weird, the more you make it clear you think it is weird. Treat your characters as being in a healthy relationship without major power imbalances due to age and it doesn't matter if there's a gap.
The extent of the age gap only matters if that difference is being exploited by the older partner. You're not writing about how to be in a relationship with an age gap. You're writing a story about people who already are. If they're comfortable, the reader is. And if not they don't have to read it.
Comments
Idk I just want this one to be like. Kind of softer and more chill than usual I guess?