Illya thought he might have actually been in love with her the first time that he saw her, back in Berlin when she was a target that he was watching, when Solo had gotten to her first and managed to get her out of the country. The more he got to know her, the more he fell. There were times on their first mission that he wanted to simply pull her in and kiss her, but he was a professional. Finding out that they would be working together longer was both a blessing and a curse. Illya loved that he continued to see her, but he felt that he could not make his feelings known because she was one of his partners.
Here? Well, technically they didn’t work for UNCLE here, so technically she was no longer his work partner.
He tried to laugh at how badly he had screwed up earlier by telling her she had good bones, but he was nervous about screwing up this moment again. “The way I care for you is more than as a friend or partner, Gaby. I have felt this way for a long time.” Illya removed her hand from his arm so that he could take it in his. “I need to know... what you think about me.”