Geno's nicknames for teachers and times of day:

English/Dream-Boss

Math/Muffet-Muffin (I only had to change two letters)

Art/Ink-Squid

History/Sans- Classic

lunch/Grillby- Grillby

teacher's lunch time- Reapers wallet

Free time-Also Reaper's credit card

Science/Science-Sci

Music/Shyren-Re-Rey

Magic/Gaster-Dadster

Drama/Mettaton-Ton-Ton

P.E./Error-Glitchy

Reading/Reaper-Free food

Dance/Fresh- Lil' bro

Get Out-Reaper's cash

--------------------------------------------------------------------------------------------------------------

As you could tell; Geno is broke, so he uses Reaper's money. I don't know how Geno is able to be broke and have part-time kids. (he only calls them 'his kids' when they're spending the night at his house)