That's pretty rare, fleas of every variant only like to live on the host they prefer, so cat fleas, etc. That's some pretty shit luck that.
I had an overnight bag which I'd left on the bedroom floor. They must have hijacked it!
The woman I was seeing had a few 'inline' bites here and there but I didn't give it a second thought.
After I'd returned home I realised what had happened. I bought some of that flea spray, sprayed the house and eventually they died out without any cat's blood, (I guess).
I'm fucking scratching now as I write about it.