O Philipp Melanchthon! . . . I appeal to you who live in the presence of God with Christ, and wait for us there until we are united with you in the blessed rest . . . I have wished a thousand times that it had been our lot together!
(from online paper, "John Calvin -- True Presbyterian," by Francis Nigel Lee [pdf / html]; his own sources provided: J. Calvin: Clear Explanation of the Holy Supper, in Reid’s Theological Treatises of John Calvin, S.C.M., London, p. 258; see an alternate 1978 printing listed on amazon and this exact excerpt -- and larger context -- from it)
The same thing is found in Tracts Related to the Reformation, Volume 2, translated by Henry Beveridge, Edinburgh: Calvin Translation Society, 1849; "True Partaking of the Flesh and Blood of Christ," pp. 496-497):
Thou hast said a hundred times, when weary with labour and oppressed with sadness, thou didst lay thy head familiarly on my bosom, Would, would that I could die on this bosom! . . . Certainly, thou hadst been readier to maintain contests, and stronger to despise obloquy, and set at nought false accusations. . . . I have not indeed forgotten what thou didst write.Further online documentation: one / two.
John T. McNeill, editor of the 1960 edition of Calvin's Institutes, mentions it as well, in his article, "Calvin as an Ecumenical Churchman," Church History, vol. 57, 1988.