Like a sexual pole vault, the woman is on all fours, and the gentleman then "leapfrogs" over her from behind, however his cock may get caught in either her vagina or anus, before he makes it fully over her.
This act can also be performed by a woman wearing a strap on dildo, to either a male or female recipient.
Fuck me, I did the rusty starfish leap with my girlfriend for the first time last night, got my cock square in her shitter first time, result.