Adrien felt guilty for spying Marinette's privacy, even though it was completely unintentional.
The moment Marinette entered the classroom, Adrien could sense that Marinette was not feeling her best. Her face was slightly more pale, her posture crouched, and her eyes a little droopy.
At first, Adrien did not think all too much of it, assuming that she didn't get enough sleep last night, but during the first lesson he could see Marinette uncomfortably moving around her seat, with her arms wrapped around her stomach. His first guess was that she probably got sick or had an upset stomach, with the latter one being more logical due to her sitting position, but once their lesson was over, Adrien overheard Marinette and Alya's conversation as the two girls were walking down the stairs.
,, You should probably go home, Marinette.''
,, I can't, Alya. I don't wanna miss anything just because I am on my period.''
She's on her period, Adrien thought, and felt his cheeks heating up. Adrien felt guilty. It was not something he should have heard or known, but his worry got the best of him, and he just wanted to know what was wrong with Marinette. Adrien knew it would have been more appropriate to just ask her personally, but before he even had the chance to do that it was already too late.
,, It's fine, Mari. I'll come over later and give you my notes. Don't worry, you got me.''
,, Thank you, Alya. I guess I'll go talk to Madame Bustier and then go home. See ya.''
With one last hug, Marinette made her way over to Madame Bustier, while Adrien tried to hide behind the staircase, not wanting to show that he overheard their conversation.
Once the two friends were out of side, and nobody seemed to be around, Adrien was wondering if there was anything he would be able to do for her. It was partially because he wanted to help his close friend, and partially because he thought it was the least he could do after listening to their private conversation.
During the next lesson it was all Adrien could think about, and eventually he came to the conclusion that he had no idea on how to help a woman when it comes to their period. He had no mother to ask for, and so the next person he thought of was Nathalie, but asking Nathalie would mean that his father would eventually know about it, and that would make this situation far more complicated. Alya was out of the conversation since that would mean, she would know that Adrien listened to them.
Jumping to conclusion that nobody would be able to help him out, he decided to spend the next break in the library, and tried to look through as many books about women's health and periods as possible. In a way it made him feel awkward, especially because of the weird look he received from the librarian, but he knew that his friend's health and wellbeing was far more important than some stares being thrown at him, and decided to just ignore it.
Today after school Adrien was supposed to have another hour of fencing lesson, but instead he snuck out and made his way to the drugstore to buy some things, and then over to Marinette's home.
It had been several hours since Marinette has been home, and yet she still felt no better than she did at school. Her bed might give her the comfort that the school could not, but the cramps were still on-going. Tikki tried helping Marinette calm down, but not even the gentle touch of the Kwami's hands were able to make her feel better. It was also getting cold outside, making Marinette shiver under the covers. It was not until somebody slowly creeped into her room that Marinette's heart was rapidly beating in her chest.
,, Hey Marinette, I hope you don't mind me coming here. Your mom already told me you were not feeling well.''
Adrien's presence was not only shocking to Marinette, but also embarrassing and unexpecting. Marinette was already dressed into her pajamas, her hair was messy, and she she was sure that she looked like a complete mess, making it even worse that her long-time crush had to witness her like this.