source: Mr. Chivalry: One Piece’s Sanji and the Downside of Chivalry – Comic POW!

stick to

1. continue or confine oneself to doing or using (a particular thing):

A〈1つの物〉を使い続ける; A〈1つの事〉に専念する.

e.g. I'll stick to bitter lemon, thanks.

not move or digress from (a path or a subject).

A〈要点･主題など〉からはずれない; A〈道〉からそれない, A〈人〉から離れないでいる

2. adhere to (a commitment, belief, or rule):

A〈約束など〉を守る, 実行する; A〈信念など〉を曲げない

e.g. the government stuck to its election pledges.