Nishinoya had always joined Tanaka in his persistent act with Kiyoko because he had nothing better to do and he's best friends with Tanaka, it wasn't till you joined Karasuno at the start of the year Nishinoya actually understood why Tanaka was like that towards Kiyoko, so here Nishinoya was with Tanaka in tow, obviously he had to drag Tanaka along, the boys asking if you needed help setting up or doing anything for the club you're in, you couldn't be bothered to turn the boys away, especially when they were so eager, so you told them politely what you needed

"You got it!" Tanaka said with a grin and pat on the back to you

"Whatever you want, momma" Nishinoya says with a lazy grin, both in attempt to be smooth and because he was so blissed out to get actual interaction with you