Even though Newt wasn't in favor of hurting you or you getting infected or turning out to be a crank, he didn't question your choice to continue the relationship with him even though he was infected. He knew that both of you were not immune to the virus, when he was infected he had been rude and rude to you so that you would give up on him, but the contamination ended up being revealed. Your choice to continue touching him, getting closer to him, helping him captivated him even more, even though he was immensely concerned about his health. "You should take the serum instead of me.", he held out the serum that slowed the virus from spreading to you as you swallowed hard. Sometimes Newt's veins would turn dark in color just because of the virus spreading, but nothing that the serum could solve.
He squeezed the object while still holding it out to you. "You should take precautions for now. I'll ask Tommy for another dose later.", he concluded as he looked up at you.