Here is my opinion, from experience with a healthy, open relationship: whatever agreements are made need to be mutual - without pressure or guilt - and understood to come with expectations of limitations and exceptions.

MEANING: as the partner, you can set rules of engagement for her, she can set those same rules for you - and as a couple, you have rules for mutual play (and in many cases, one solid rule is no solo play)…

Advice: don’t let her guilt you into something you are not comfortable with… if her motivation is to have sex with other guys, she needs to be clear about that intent AND give you a chance to agree or disagree (and then choose to accept it and stay in the relationship or reject it and leave the relationship)…

It doesn’t sound like a good thing, especially if she is already changing her mind about group play and wanting to keep you out of her sex adventures.

Good luck, OP