I'm absolutely fuming. My 4 year old son spends every Wednesday night at his dads. I've just drove…

I'm absolutely fuming. My 4 year old son spends every Wednesday night at his dads. I've just drove past his house to find him stood outside smoking weed and drinking a can whilst my son was upstairs in bed still wide awake! I've just took my son off him as I can't trust him at all now. What would he do if my son needed to be taken to hospital and he's high/pissed?! I'm so angry! This is the last thing I need at almost 37 weeks pregnant! I genuinely thought that he was a doting father that wouldn't put his son in danger but I was obviously wrong. 😡😡😡😡