In DIK playthroughs MC dont tell Heather and keep the secret. DIK code will be kept at all times for those playthroughs. In chick or neutral ive decided for MC to not honor the DIK code at all unless it serves Fuckface or costs him nothing to do it. Tommy is not really bad I think, not yet, doing hard drugs doesnt make you bad but it can easily make you start doing bad shit. Lets call him a troubled person thats spiraling and have yet to hit rock bottom from his own actions. Already on a violent and drugged up path he needs to crash and burn to turn shit around out of his own choice. Helping Heather is the human greater good option.
MC is not that smart to me, as he is drawn to drama. MC is either a whipped simp (chick) or fair minded (neutral) and wants to tell in both cases, or he is loyal (dik) to the code but otherwise doesnt care and will fuck her regardless because its an open relationship.
The smartest choice is to keep silent, othervise Heather could easily narc
and make Tommy really hostile and its the choice i personally would do as I wouldnt want to be involved in the drama. But thats not the MC and thats not the MCs motivation I think.
Look for the walkthrough that MrBubu made. edit:
MrBubu