|This is the right kind of cat loving partner - blanked for privacy
For us cats it is much simpler. We get in the mood, we go out and find others, and we get it all over with lots of caterwauling, lots of partners, and lots of sex. Then we come home and wait for kittens. We do not worry about what happened on the roof that night.
Separation is not always bad for cats. When one human leaves, there is more room on the bed for us. There is usually more human attention, even if the tears and would-be hugs (which most of us hate) are an embarrassment.
Sometimes we need to rehome a new partner that is ruining our lives. Of course we can put up with less space on the bed, and we can put up with more interruption from the two humans. But occasionally there is a partner that does not like cats.
These are people, usually male humans, that keep us out of the bedroom. The cheek of it. I don't mind sharing my bed with a human but being pushed off it altogether is too much.
How to deal with this? Show very obvious terror every time the bloke is around. Mew piteously and give that helpless look to the female. Shiver - yes, I know that cats don't shiver from fear but most humans don't realise that.
If she loves you enough, she will get the message and rehome him. If she doesn't start visiting neighbours to see if you can rehome yourself.