1. He'd know, and there would be no secrets between us
2. He could offer support
3. It could strengthen our relationship
1. He would probably dump me
2. He'd think kissing me is disgusting
3. He might tell others
I can imagine him reacting in two ways:
The first way is where I tell him, and he hugs me. And then he asks what he can do.
The second way is where I tell him, and he hugs me. And then he says he doesn't want to date me until I'm recovered.
To which I would have to reply: "That could be forever."
I don't think he'd dump me because of disgust, although he might be disgusted either way.
Last time I told my bf it went really well. We cried about it, shared secrets, and accepted each other. And he tried to be a support for me.
I think maybe waiting a longer time might be a good idea. Until he's hooked, and then there will be less of a chance that he'll dump me. The other thing with that is that he might construe that as me having lied to him during our relationship, which would not end well.