To be candid i bet to differ, relationship thread on love and affection you both have for yourself which is also strenghthen by copulatuon,sex and whatever.
There is every probability that if the guy knows about it he will check out of the relationship, so why play with probable when you can stick with possible, I am of the opinion that you keep it to yourself and wipe your tear, its not the end of the world dear.
And for anyone who may want to come for my head, let's come to think of it because I want to put myself in his shoes, I will never forget that and even if I chose to let go, I will definitely remember while having sex with her.
No one without skeleton in their body, just so well to love him more and appreciate him better, telling him this will only worsen the case no matter what. Even if the guy chose to be a good guy, future can't be guaranteed.
People will forgive us if we make a wrong decision but posterity will never forget us if we didn't make a decision atall..
Thanks you