At least with Chloe she didn't actually know the relationship status of Jermaine as he wouldn't tell her. Roxanne has made it clear to everyone in the house that she's engaged and loves her partner, yet Ben keeps trying to force something with her and asking her questions almost to try and change her mind
Look at the start of tonight's preview... it's totally unacceptable and not fair to put Roxanne in a position like that.