There was a party at the Thousand Sunny, everyone was happy dancing and drinking.

And as always, you weren't good with alcohol. When you were on your way to your room, drunk, you tripped but Sanji, who was coming out of the bathroom, managed to catch you. You stared at him, and without saying anything, you kissed him. Sanji knew that was a bad thing, since you were drunk, he felt bad for not having taken you away from him instead of reciprocating you

So the next day he was avoiding you.