Ernest Hemingway once said(and I am paraphrasing) "When a man can't have sex, he will satisfy himself by killing something" it was surmised roughly ten years ago that Space Marines are at least sexually active when they are Scouts, as they are still maturing, and in the company of others just like them. The idea of a Spartan, Greek, or Viking "Warrior bond" runs throughout the early fluff of 40k. It is not inconceivable that they may discontinue such activity, especially since these bonds have already been established.
And a final note, Leaman Russ is loosely based on Beowulf, just as Horus is based on Lucifer, and others that have already been mentioned.