Maybe Dan was a little older but wizards lived a long time, it threw age off into a strange thing that didn't matter so much. As long as you were adults, consenting and without some kind of power imbalance it all seemed good to Bill. "Careful of your hip there, sugar," Bill said as he gave said hip an affectionate squeeze.
Even if Dan was older, Bill was probably the more experienced of the two, he was the one making sure he was comfortable with him before he did something stupid like came on too strong.
He seemed so surprised and Bill turned back to take a look at him. How could someone so gorgeous be so clueless? "Of course I'm making you dinner, you want to date me, you get the full experience. Dinner, books, breakfast, anxiety, issues, I got it all," Bill teased. As for magic he nodded, finding it fun that Dan didn't really know much about his kind of wizard. "Quality of the food depends on the person making it, just like doing it the muggle way," Bill explained.