What sort of advice are you / your mate looking for?
She’s married – assuming for better or for worse – and there are two kids.
High five your mate as he’s getting some milf action but in reality what happens when it all comes out?
Which it will because kids have the great ability of asking the wrong question, at the wrong time in front of or to the wrong person.
If he can’t afford to live anywhere else then where’s he going to go?
If the husband is have mental problems how’s he going to react?
How is the milf going to deal with her kids when they get upset?
One things for sure, if she’s a decent mother your mate will be out of the door the moment the kids are upset. Which loops back to his accommodation dilema.