Sayyiduna Shaddad bin Aws (may Allah be pleased with him) narrated: I was with the Messenger of Allah (peace and blessings be upon him) on the eighteenth of Ramadan, and he (peace and blessings be upon him) saw a man being cupped, and he said: "The one who cups and the one who is cupped have both broken their fast."
Hadith Referenceالمعجم الكبير للطبراني / باب الشين / 7123