HIM AGAIN: Never one to give up his 15 minutes, Kevin Federline is a tabloid cover regular, and this fall there was the arty aberration of L'Officiel Hommes' cover. Now the former Mr. Britney Spears is on the December cover of Details, shot by Steven Klein and out in a few weeks, according to a source. (For the confused who think the December issue is the one on the stands with Jonathan Rhys Meyers on the cover — surprise — that's the "Holiday" issue.) It'll be Federline's second time on the cover: in March 2005, editor in chief Dan Peres did the Q&A himself and was joined for part of it by Spears. Those were the days of evident domestic bliss: "S--t, I could go on forever about my love for this girl...I could be sitting at home doing nothing, I could be playing f--king video games. She's more proud of me than anyone has ever, ever, ever been in my lifetime," Federline said then, going on to test that very theory — apparently unsuccessfully. Despite his candor, Federline wasn't a particularly good seller for Details in 2005: at 61,179 on the newsstand, it was the second worst-selling issue of the year, though that was flat compared with the same month in 2004. A spokeswoman for the magazine declined to comment on the cover or who did the interview.