The phrase "interpret that? Is it really an open invitation?" appears to be a request for someone to analyze or understand something, possibly an invitation, in a given context.
Without additional information or context, it's difficult to determine the exact meaning. The meaning of the phrase depends on the situation, the people involved, and the context of the conversation. It could be a straightforward question about whether an invitation is genuinely open or just a rhetorical question expressing doubt or skepticism.
If you provide more context or specific details about the situation, I'd be happy to try to offer a more detailed interpretation.