i would say fuck it and no hard feelings towards him, even if he was fuckin my (pretend) baby mama. I mean whoever she's fuckin aint up to you. and sometimes you cant help who you feeling or got feelings for. A bitch is just a bitch mane, lose a hoe gain a hoe, that what i was taught. You should be more strong minded than to hold that grudge and not go to your boys funeral. thats your chance to get out what you gotta say to him, and make peace (for yourself and your own mind) before he get put in the ground.
would you rather think about him fuckin your girl in the ass the rest of your life, or think about all the times ya'll used to kick and be homies, gettin in trouble together?