Julia is cheating on Martina

I think the flirtation between Julia and Adriana is totally unacceptable and if I were Martina, I'd be embarrassed and pissed. Do they have an open relationship? Does anyone know what the deal is? I really hope Martina gets some air time at the reunion to share her thoughts after watching this season. I want them both to be happy, but I need to hear from Martina that she's cool with what Julia does behind her back.