Lewis & Short

fŭtŭo, ui, ūtum, 3, v. a. [supine stem from root fu-, cf. Gr. φῖτυς, φιτόω, φυτεύω], to have connection with a female (rare), Cat. 97, 9; Mart. 10, 81, 1; 3, 87, 1.
Absol.: te futuente, Mart. 9, 3, 10.