I may be totally wrong, but doesn’t he say “I can’t leave her“?
Robin said “I can’t leave her here.” The “here” is very important because to leave the word out changes the meaning of his statement to one about whether he is staying with Zelena, when it is a statement about Robina and Zelena’s location.
Adam & Eddie always choose their words carefully. The “HERE” part is all telling. In my opinion, Robin isn’t saying he can’t leave Zelena; he is saying he can’t leave her in NY because she’s pregnant with his child, so he must bring her back to SB with them. He has no intention of staying with Zelena. He only wants to keep his eye on her until the child is born or they find out she’s been lying.
Keeper of Pandora's Box & The Yellow Brick Road.