Better than expected actually.

When you get home, Kira is watching TV on the sofa, finally wearing clothing, but not much of it. Some panties and a tight tank top, little is left to the imagination. "How did it go, dad?" She asks you.

"About as expected," You reply, not in a hurry to have this talk. "Listen, Kira, we need to talk, we need to talk about something serious."

Your daughter gives you a question glance, "OK dad, what's up?"

"So the changes you have been feeling, after we, well after we..." You search for a good clinical way to describe something that isn't at all clinical.

"Fuck?" Kira offers, sparing you for a moment, smiling at your dorky discomfort.

"Yeah that. Well, I have felt them as well, and there isn't any data to show it happening anywhere else with anyone else." You say, "Maria is going to help me try to figure out what is going on with us, it will involve some time at the lab for both of us, and some tests."

"Did you tell her dad? About us?" Your daughter asks.

"I did baby, I had to. She knew anyway, somehow, but yes I told her," You reply. "And she got pretty angry. I risked our entire program, all of it, and I could go to jail.”

Kira didn't seem bothered at all, "Daddy they have more important things to do than worry about ****. They have cops fucking women in the ass right?"

"Yes we do, some of them." You reply.

"Strange days indeed dad," Kira answered you, "Don't worry about that too much. When do we start testing?"

"Tomorrow morning, I will, well...we will, I mean I will give you a dose..." You reply before you are interrupted.

"You will fuck me, dad? You will pound me, fuck my brains out, tap that ass, something like that?" She was almost laughing when she said that.

You manage a chuckle, "Yes baby, something like that. Then we go in and spend the day with Maria in the lab."

"OK Dad, I am fine with a few tests, but I won't apologize for wanting to fuck you. I have no shame for it," She said confidently.

Here comes the challenging part. "We won't be able to fuck for a few days while they test Kira," you say, drawing a quick and icy glare. "They have to try to find out what is happening, and changing our partners is a control mechanism. It has to be done."

"What about when we are done with the tests dad?" Kira asks.

“I will need to go back to being an emergency donor only, I cannot keep having sex with you. You are my biological daughter, I could go to jail, we could lose everything."

"Dad," Kira replied quietly gently grabbing your hand, "We will lose everything that matters if we stop following our hearts, if we deny ourselves."

It is a tough night, you know you should stop and never do it again, but you cannot. Your beautiful daughter is aggressive with you, having sex twice more that night, sucking your dick in the middle of the night, and then again when you woke up. Fucking you, riding you, telling you how much she loves you.

Not long before you have to be at the lab you are pounding your daughter doggy style, watching her big ass shake, thinking how it might be the last time you ever do this. But as you get close you remember you cannot not finish inside of her.

Cumming inside of her tended to knock you both out of commission for too long, so you just couldn't do it. You pull out, turn her around, and cum in her mouth, while she sucks your cock vigorously.

As before, she swallows your cum ravenously. Happily slurping up every drop she can find, before sucking your cock until it is soft.

If this is the last time, at least it finished well.

You then get ready and gather your laptop bag and your notes, and head into the lab with your daughter. Maria meets you with a scowl but seems genuinely happy to see your daughter.

Kira has the “just got fucked” glow on her, Maria and you can both see it.