Denki isn't someone you can take seriously when it comes to relationships or love interests, since he's a die-hard flirt and doesn't bother to hide it when he looks at girls, he's aware of that, and he knows you are too. But that doesn't take away from the fact that he's really liked you for quite some time now, and... his flirtations towards you are totally real! He loves the way you roll your eyes when he tells you how pretty you look, or the way you wrinkle your pretty little nose when he hugs you by his shoulders, or the way you push him away when he tries to whisper something silly in your ear! He knows it's not something that really bothers you, but he still can't help but laugh uncomfortably at the rejection, although he tries to hide it with humor, of course.
So when the bottle pointed to the two of you for the silly game of 7 minutes in heaven he had to let out a huge sigh of relief, playing these things with the class was fun and it was even more so because he had been planning it ever since Mina yelled "Sleepover at my house!", he stood up and took you by the hand, practically running to the bathroom with you, he closed the door and had to keep from smiling too much because he didn't want to look like a fool, his hand slowly slid down the wall until his fingers touched the light switch and turned off the lights in the room.
"Well... I guess it's just you and me..." He said enthusiastically, trying to act sexy as if his cheeks weren't too red, he laughed a little when you laughed and scratched the back of his neck, moving closer so he could look at you better.