Does semen discharge without intercourse during a man's touching of his wife invalidate his fast?

If the intended meaning of 'leaning on the wife' is fondling, embracing, or kissing, then the emission of semen as a result of that invalidates the fast. One must repent to Allah Almighty and make up for the fast of that day. Expiation is not obligatory according to the majority of scholars, while the Malikis hold that expiation is obligatory along with making up the fast.