to cheat on sb in Polish:

1. zdradzić kogoś

Polish word "to cheat on sb"(zdradzić kogoś) occurs in sets:

Iwka 18th Nov 2016 (2h = 1h + BONUS lesson)
Karolina 31st March 2015 (1h 15min)
Iwka 21st Oct 2016 (90 min)
Karolina 19th Feb 2015 (6)
Karolina 21st July 2015 (50 min)

2. oszukiwać kogoś

Polish word "to cheat on sb"(oszukiwać kogoś) occurs in sets:

Idiomy i phrasal verbs