Everything is so complex like when you see xyz in maths together. But we must not always fulfill oru sexual desires or it's destruction for us. Best thing, break up with XYZ and forget about the second friend. It's always not worth the trouble to destroy friendships

Yep, in this equation XYZ's Second Friend needs to be eliminated - this will both save friendship and get rid of temptation. XYZ also needs to be eliminated because He does not love her and it is not fair to keep stringing her along.
Finally, He needs to know that he can control this equation.

Hah! My time in calculus was well-spent!!

@Pippa
You got a good grasp of calculus. I'm in need of a refresher course, I only understand debits and credits now.

They probably both know what they are both up to and they have no qualms with it. The chic probably "cheapified" sex which made the guy also interested in XYZ's second friend

When I took a shot at the equation above and said that eliminating XYZ's Second Friend will save the friendship, I was referring to the friendship with the guy's second friend. It should not matter to guy how his second friend is involved with XYZ's Second Friend. The mere fact that one's friend is involved with a girl to whom one harbors some attraction should be enough of a deterrent to stay away from that girl out of respect/loyalty to one's friend.

If girl in above equation wants to pursue guy, then she has to break up with guy's second friend and guy should play no role in this. Of course, guy would have had to eliminate XYZ way before this happens.

I got confused on the 3rd line