I read a lot of gossip/showbiz magazines and I can't say that I've ever seen a lot of Dec and whoever he's been going out with in them.
As for the fact that the Daily Mail is making a big story out of, this is the same paper that almost every day features a story about Suri Cruise's latest oufit/getting an icecream/just leaving the house, so it's hardly a good marker of how big a story is! I'd take it more as an indicator of a slow news week, which the past week has indeed been.
Funnily enough, I was watching Britain's Got More Talent last night and the new Ant versus Dec game, which involves them playing old style games against each, is called 'Gamelord'. Last night Dec won, leading the crew to shout 'Gamelord! Gamelord'! at him, with Dec responding by laughing whilst saying, 'That's GAME Lord, GAME lord'.
And there was also the guy doing a very camp impression of him on the main show, which he didn't seem too bothered about. I'd have thought that if what is being hinted at is the case then he wouldn't be so relaxed about that kind of thing?
Yet there is something a bit off about the 'fond memories' quote, and the fact that he's never been able to settle down does seem a bit odd. I'd give it all odds of 50/50 to be honest, and perhaps we'll never know the truth.