Unfortunately, tabloids like Josei Seven are only so trustworthy. They do have some 'scoops' once in a while but when it comes to Ayu, they're usually pretty wrong. I think the basis for this rumor is that Tyson apparently wanted Ayu to get fatter. I guess it's hard to believe because Ayu got a lot of fitness tips from him since he's a gym rat.
There's more here if you want to see it:
http://news.livedoor.com/article/detail/10361311/
At the end, they seem to mention that they contacted Ayu's management and their relationship is okay.
Seriously, why do these tabloids choose the absolute weirdest pictures of Ayu when they post rumors?
And as usual, a lot of netizens want Ayu back with Nagase, lol.
From @
BartCHUUUUO
These articles seem to say that he was left in Singapore or whatever by Ayu, but it doesn't seem that way.