Cute.
Pretty good premise for an actual series.
"After I graduated I started dating my teacher I've been in love with for three years"
I'm trying to think of any series that actually have that premise. I know of a few that some continuation after the graduation, but they usually ends fairly quickly. I guess authors just like skirting the line of the taboo. I'm pretty sure I've seen at least one that has a former student coming back into a teacher's life years later, after having had a crush on them as a child.
A series that began with them starting to date, with the teacher still working and the younger one in college, could be interesting if it focused on the difficulties such a couple would face. Even if the technical power balance is gone, there is still the danger of the appearance of (intended or not) grooming. It's easy for us, the audience, to know things were on the up-and-up, but harder for other characters in the story. So facing increased scrutiny and doubt, and reasonable people being put off, wouldn't be a bad thing for the story to examine.