Uncouth!

Gemma remained calm as Helen walked angrily toward her, her eyes staring daggers. She looked like she was going to murder Gemma.

Gemma knew Miguel to be an asshole, but she didn't think he would take it this far, by deciding to flaunt his mistress in her face. So this is the reason he has been checking his time just so he can go and be with her? 

Why then did he ask her to come? If he wants to be with Helen, he should have just gone to be with her. After all, this whole idea of coming to see the house where she was going to be living in, was all his and her mother's idea. The first time those two ever agreed on something and this is the outcome. 

"What the hell are you doing here?" Helen demanded in anger as she came and stood in front of Gemma. The way she was vibrating with anger, one would think Gemma stole something precious from her.