I wouldn't say no to something

Từ điển Oxford Advanced Learner 8th

I ˌwouldn't say ˈno (to sth) idiom
(informal)used to say that you would like sth or to accept sth that is offered
•I wouldn't say no to a pizza.
•‘Tea, Brian?’ ‘I wouldn't say no.’
Main entry: ↑say_idiom