Responses
I think it’s this
http://www.mangago.me/read-manga/kiraide_isasete/
this one maybe?
Kiraide issasete
THANK YOU GUYS!!
Where this omega works as a janitor for a high school (has black hair) to support his daughter that he had due to a asshole alpha taking advantage of him, so he sworn of love I think. Anyway this student(is also an alpha) was like I love you (he had silver hair) and that's all I remember, please and thank you!