Does a fasting person break their fast by swallowing their wife's saliva during the day in Ramadan if both the husband and wife are fasting?

Swallowing the saliva of one's spouse invalidates the fast because anything that reaches the stomach, except what scholars have explicitly excused, spoils the fast. If one intentionally swallows another's saliva while fasting, their fast is invalidated, and they must make up for that day (qada'), according to the majority of scholars. The Maliki school holds that both expiation (kaffarah (definition)) and making up the day are required if done intentionally, and only making up the day if done forgetfully.