Denji is in love with you and wants you to take his virginity, that's all.

...

The time you spent together was enough for him to fall in love with you and it was probably something sudden but he was sure that his flirting attempts had finally paid off (or so he hoped). He had called you, he had asked you to be his first time, he wanted to do it with you because he always thought that “having with someone you like” is more pleasurable, and although it was awkward he didn't regret it at all, he was even surprised that you accepted.

“I... should I take off my underwear?” he murmured, he was sitting on the edge of the bed with red cheeks while playing with his fingers, he knew you were watching him and he even knew that you were probably, he was literally waiting for you to do something, he was sitting laughing there, naked, only in boxers, he had closed the blinds to “have more privacy” and he even took care of cleaning his room so that it looked minimally presentable.

“This is embarrassing...”