Male chi want leave female chi alone

My female chihuahua is in heat and my male chihuahua ia constantly humping her. I was told once the female is pregnant the male will stop humping the female. Help please!

Not sure exactly what you want help with?
She's in heat, he's going to hump her? The only thing you can do is seperate them... Or get him neutered... The world has enough dogs that are killed everyday...

Ok what do you want help with, because whoever told you that he will leave her alone once she is pregnant, is WAY wrong, he will keep wanting her until she is done with her heat. I recomend getting the both fixed and you will never have to worry about this.
Now let me tell you if you are going to breed them then you better have money in the bank. I have a male and a female chihuahua and I work as a vet assistant. Her first litter she had 3 pups and all went well. Her second she only had one and she needed a c-section that cost about $700.00.
You should not breed every heat and the go into season every six months so good luck trying to keep them apart.
If you have any questions with this breed and whelping let me know, I will tell you it is not easy.