"That won't be a problem if you go back to being human later, right?" Tiffany said
"Yes, you're right." Nikki said
"I believe we already have what the doctor wanted to know, but I'm still horny. What do you think of one more round?" Tiffany said
"I don't think this is a bad idea." Nikki said
"Oh, and Maya, you can join us if you want." Tifffany said to the dog girl jacking off in the corner of the room.
"Can I really? I won't mess up the test?" Maya asked
"No problem, the test is over. But the doctor never said we would have to come back immediately after we were done, so we can use the time for one more time." Tiffany said
Maya then got up and joined the lamias, where she started by stroking their dicks with her hands until they were fully hard again.
Nikki then hugged Maya and said "I can't take it anymore, I need to do this." and quickly stuck her cock in the dog girl's pussy, fucking her heartily. Tiffany didn't stay still, she got in the back and started to fuck Maya's ass.
As the lamias fucked the dog girl Nikki mutated again, just like her first time with Maya her face and ears became canines, three new pairs of breasts appeared in her belly and a dog tail grew behind her, just above where her snake tail began. She could feel her dick changing too, so she took it out and saw that although it was still a snake dick, it had a knot like a dog's. In the end she had become a dog girl lamia.
"This is interesting, very interesting." Tiffany said
"Please leave the conclusions for later, just keep fucking me." Maya said complaining about the break
"You're right." Nikki said and went back to fucking the dog girl. This time she took advantage of the fact that she had eight breasts and joined hers with Maya's, making them rub against each other.
"That's right... our lower breasts... my cock.... ahhh, that's so good." Maya said, because even if it wasn't intentional her bottom pairs of breasts ended up titfuckung her dick.
Soon Nikki gained more stimulation when Tiffany passed the tip of her ass underneath and stuck it in her pussy. "Great idea, it's a great way to use a tail." she said and did the same, managing to find the nurse's pussy and tail-fuck her.
They were all on edge and soon they came one after the other. With the end of their orgasms, they were finally satisfied for now. They regained their breath and had to wait as Nikki's cock got knotted in Maya's pussy.