Guys, my boyfriend called me Senpai, but he's older than me. What does he mean?

Anonymous
Ok, so me and my boyfriend are TOTAL Weeaboos, and he called me Senpai. I know "Senpai" means "upperclassmen", but why'd he call me Senpai? I have no idea what it means.
Guys, my boyfriend called me Senpai, but he's older than me. What does he mean?
3 Opinion