I iust imagine this as the worst romantic ending. Star's feelings for Marco hitting her in the face right as Marco makes some major sacrifice that will mean never seeing her again. Either she already knows she's in love with him as they say their clumsy goodbyes and he enters some portal that'll never open again or it hits her while he's waving goodbye from the other side of the gate and she's doing her best to keep a strong face until he's gone for good >.<