Your body is yours to share with who you wish.
If you do not wish to share it? Don't.
What kind of open model relationship
are they wanting? They sound like they want swinging. You sound like you want something else.
Any hope of people pointing to something on the list and going "THAT one. That is what I am after here" so you all can at least get clear on what people want/expect here?
As for jealousy -- what's that speak to?
Are you doing all of page 5 for yourself? Are they doing page 6 for you and giving support? Or leaving you out on a limb / minimizing / putting you down? What kind of support/nurture can you expect from this open relationship -- whatever model it is? Do you feel emotionally safe in this relationship?
You have the right to want what you like best in your romances. So does everyone else. If all the wants do not match up -- then there's some choices to make and things to reconcile.
Hang in there. BREATHE.