Hij is getrouwd met (2) Edna St. Vincent Millay juli 1923 te New York, hij was toen 43 jaar oud.
Eugen Jan Boissevain, geb. Amsterdam 20 mei 1880, [koopman te New York], Boston (Massachusetts) 29 aug. 1949, tr. 1e Londen 14 juli 1913 Inez Milholland, B.A., L.L.B., geb. New York 6 aug. 1886, voorvechtster vrouwenkiesrecht, Los Angeles (Californië) 25 nov. 1916, dr. van John W. en Jean Torrey; tr. 2e New York juli 1923 Edna St. Vincent Millay, B.A., geb. Rockland (Maine) 22 febr. 1892, dichteres, Austerlitz (New York) 19 okt. 1950, dr. van Henry Tolman Millay en Cora Buzzell.
This quote, from Alyse Powers, one of his second wife's former lovers, describes Eugen:
"Handsome, reckless, mettlesome as a stallion breathing the first morning air, he would laugh at himself, indeed laugh at everything, with a laugh that scattered melancholy as the wind scatters the petals of the fading poppy...One day his house would be that of a citizen of the world, with a French butler to wait on the table and everything done with the greatest bienséance, the next the servants would have as mysteriously disappeared as bees from a deserted hive, and he would be out in the kitchen washing the dishes and whistling a haunting Slavic melody, as light-hearted as a troubadour. He had the gift of the aristocrat and could adapt himself to all circumstances ... his blood was testy, adventurous, quixotic, and he faced life as an eagle faces its flight."