"she’s worried he could be using the relationship for fame"
I find this hard to believe, I don't think that came from Sarah at all. He has moved country, gone back to doing what he was doing before CBB and hasn't given any interviews. That's the complete opposite of "using relationship for fame". If he was going around doing interviews and talking about her, fine, but he has not even appeared in the media at all. So, that's a bunch of rubbish.
He couldn't be further from "using it for fame". First of all, he hasn't even spoken about her or CBB in like 2 weeks
He's doing what he was doing before, he's back at work etc...