Michael comes up with a compromise.

The two girls stood glaring at each other, neither prepared to back down.
"I'm a bit worn out from all the surfing and travelling that Robs has been putting us through lately. I don't think I'd be up for a big night," Emma said triumphantly, thinking she had felled Robyn's ambitions towards Michael.
"I'm not actually that hungry at the moment, so I don’t think I'd be interested in getting anything to eat right now," Robyn countered with a sneer.
Michael who had been facing Robyn as she spoke didn’t see Emma stick out her tongue in retaliation.

Michael quickly realised this situation required a bit of diplomacy. He didn’t want a catfight breaking out in front of him, as much as the visuals in his mind entertained him. "Perhaps I can come up with a idea," he offered.
Robyn and Emma both nodded their accent, eager to break up the stalemate that was forming.
"Well, what if Emma and I go and get something to eat now and then Robyn and I can go out together later tonight?" Michael suggested to the pair. This way he could keep the two of them apart to prevent any animosity breaking out and it also gave him a great chance to catch up with both of them individually.

"Excellent idea Michael," Emma quickly spoke up realising that she would have first shot at their hunky friend. "Let me just grab my bag."
As Emma returned to the tent to get her little handbag she whispered to Robyn as she passed, "I wouldn’t be surprised if Michael was too worn out to got out later tonight either."

With there being nothing Robyn could do to swing the situation into her favour right now she would be gracious about things and see the pair off as the headed towards the car. Just as Emma and Michael were about to get into the car she overheard Emma say, "I'm a bit skint at the moment Michael. You wouldn’t mind paying would you? It's just that Robyn and I haven't been able to find much work recently."
Robyn couldn’t hear what Michael's reply was but she was fairly confidant that Emma would be able to score herself another free lunch.

Robyn returned Emma's gloating wave as they drove off and headed back to her tent to plan for her opportunity this evening.