The end result is that Munchkin is often in heat, and the object of her desire is Neko. She follows Neko everywhere during this period, cooing and clinging. Neko is amazingly patient, and every once in awhile gives Munchkin a few playful bites that seem to scratch the itch.
Neko, because she lives among cats, does many catlike things. For example, she finds small and tight places to sleep in. She also licks her paw before using it to scratch behind her ear. Stuff like that. Just now, I found her in one of her favorite tight spots, inside the mail basket under the table near the front door. When she thinks I might be going out without her, she will jump up on this low table and position herself next to the basket where we keep the car keys. Don't leave home without me is the message.
So here's Neko, in one of her favorite spots. But she's not alone. Munchy is in heat:
I have also seen Munchy get inside Neko's basket of toys and lie there, waiting for Neko to choose her as the preferred thing to chew on.