I'm actually trying to figure out for the life of me what bad advice the therapist is giving? Can you clarify this more specifically?

We can't presume to know what the outcome will be with the first ex so our opinion or advice on this is purely subjective and may be incorrect on either side.

Exploring his feelings doesn't sound like it's saying he should do anything that I would deem immoral or unethical behavior so I'm not sure where this is wrong either.

Lastly the "even if it's not wise" I'm not sure if this is based verbatim on what the therapist said or if that's your added embellishment but I would venture to guess that the therapist is actually not telling him to go ahead and be foolhardy aat all.

Keep in mind what you hear from his explanations of what his T said are second hand and through a filter of his and you may not know everything that was said behind closed doors and are missing context likely..

Try to be less overbearing about what you think is right for other people and give your advice and opinions when welcome but know when it becomes something that will cause a rift which you clearly have made apparent here by his annoyance at your continued dialog about it.

don't get me wrong, I know you're worried and this is an age old situation with friends, family and other close people... sometimes we want and do offer advice and want to do all we can for these people but our hands are tied outside of speaking our mind... again, until it's unwelcome.