HELP!!!

I have 2 new puppies that are being potty trained and I am failing miserabley!!!! I have a three year old hairless chinese crested, named LULU. We got LULU after she had already been potty trained. About three weeks ago we bought a hairy chinese crested also; took in a lost puppy in the neighborhood that lost its mother. The puppy was sooo small, veternarian said 10 weeks. I couln't turn it out. Now I have 2 puppies to train. I am trying really hard and reminding myself to be patient, but hope is fleading fast for me. I am trying to kennel train them. I don't leave their food and water out. I take them out 15-20 minutes after they eat. I dont't leave them out unattended. My problem is, no matter how many times I take them out, or how long we stay out. They will peepee outside but not the other. That is until we come in. Most of the time within a minute of coming in they decide to do number 2 in my livingroom floor. What can I do? Any suggestions will be greatly appreciated!!!!