Sure, Pal by Nikki Paris

Sienna:
Please excuse me while I go choke on my jealousy. Ava gets everything she wants, including the guy I’ve always loved. But Ava is my best friend, and she’s always been there for me, so despite her faults, I want her to be happy. I should just get over Evan because he’ll never be mine. It doesn’t matter that sometimes he looks at me like he understands my goddamn soul. It doesn’t matter… I can’t have him.

Evan:
I take the easy path far too often. I know it. It’s my fatal flaw. I asked out the wrong girl because it was easy, and I just kept dating her because that was easy, too. But it’s the hard things that define us. And it is hard as hell to be in love with your ex-girlfriend’s fiercely loyal best friend. I should get over Sienna because she’ll never be mine. I already messed that up, but I can’t get her out of my head.