chicki, I know H should not compare OW to you. People are different in many ways that's why we are unique. I would suggest that H should respect your decision to NOT take the kids around OW since you all are still M. This will create more problems than anything else. The kids should not be between the R H has with OW, not yet - it is too soon for all this drama.
You can find out about a restraining order for OW but for you to have full custody when there isnt a D then there is a problem. H still has all the legal right to take kids anywhere but if you feel that the kids well-being would potentially be jeopordized by being around OW, then do the restraining order.
See the W, Listen to the W, but dont Speak back to the W. Bridle your tongue...