Nebula's

Nebula was happy Gamora had accepted her as her sister, but in the back of her mind, Nebula always knew Gamora was the favorite daughter of Thanos. Not only that, but the other Guardians of the Galaxy all liked Nebula more than her.

Being a colleague of Peter Quill had its advantages. Nebula had kept ties with some of the Ravagers she had met, and through them, came across a very powerful ****. It was an incredibly powerful aphrodisiac and Spanish Fly. She just had to slip it to Gamora.