I don't know why men think that b/c it's on line it's not real.....where this concept comes from i have no idea.
I also met OH on line and it is very real.
If we wind back 50 years, you find a load of scented love letters hidden in a box. OH says it's harmless flirting and doesn't mean anything. Would this be any more or less real?
To me, it's the same thing...
It's cheating, simple as.
I am so sorry you are going through this

and I am sorry he is being such an arse as to brush your feelings to one side.