~~Does Olivia know you're not a cis man? If they know you're genderfluid, they're basically 1. denying your identity and 2. outing you to others, both of which are concerning.~~ It looks like Olivia is trying to affirm Alex's gender (Alex is transmasc, not transfem).
Emma is not just inappropriately sexting in a group chat (presumably without consent) and when that makes you (reasonably) uncomfortable they 1. dismiss your boundary and 2. insult you. This is the behaviour I would expect from a sexual predator.
Personally I wouldn't want to continue interaction with either of them ...