Hi Kitty,
Do you know why he reacts this way?
Did something happen that involved water?
Chase
The best thing to do is to show it to him. There's no magic that you can do to make him unafraid of running water, except time and patience. Show him different types of running water, sink, bathtub, hose. Even let him sit in a little water in the tub and pour water out of a cup into the tub. As time progresses he will become less and less scared as he forgets whatever happened to make him afraid in the first place. As he becomes used to seeing running water, and you showing him that it won't hurt him, he will cry less and less.
If you think that either one of them did something to him, considering how he's acting now, they must have done something that traumatized him, I would not leave him with them alone again if you can help it, unless one of them is willing to be upfront and admit to what happened.
I hope this helps, if you have any further questions, feel free to ask, it costs nothing to click reply. If this has helped, please remember to click the green accept button.
Warmly,
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