Mr. Potter (гет)

His lips twisted, pulling to the side. “You know, you’re the only one of Harry’s friends who still calls me that.”
True. Everyone else had started calling him James around fifth year, but not her. Calling him Mr. Potter reminded her of who he was and drew a much-needed line in the sand, even if her libido often liked to ignore it.
“It’s your name, isn’t it? I mean, that is to say, you are Mr. Potter. It’s only polite.”
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AU in which Voldemort never existed, there was no war, and everyone lives. James and Lily were teenage parents. Basically, Mr. Potter is a DILF.