Am I in the wrong through out all this with my gf?

okay so not to long ago my girlfriend went to a dance that i wasn't there for because i had some fights i had to go to, being a mixed martial arts fighter. so i guess at the dance she was grinding with this guy she had supposedly liked for a while..and expected me not to get upset or anything about it after i had asked her not to dance with any guys while she was there cause really it starts drama with other people seeing it and what not questions and rumors start forming and everything so i just wanted to avoid it by simply asking her just not to dance with other guys but i guess she just couldn't resist.....anyways i was training tonight and we were doing jiu jitsu and i was told by my trainer to grapple with this girl for one round, and she got all pissed off about it like there was something i could do about it...really i guess she just got really jealous. she thinks this is the same exact thing...but i disagree because she's dancing with a guy she has had a crush on..while i was putting a girl i had never met before in a submission