Missy,
When people have been going out for years and then break up, it's NOT because the last few weeks one of them has been irritable! But it points to other underlying issues in the relationship.
I fear that if your friend were to tell this guy, she would be leaving him with no option of backing out. No guy is going to let himself be a cold hearted bastard who won't stand by a sick person and help them.
So, I think your friend should bite her tongue, get over this guy, and concentrate on her recovery and getting her life back on track.

Just my thoughts, best wishes and good luck to your friend!

CasperTG

__________________
You know, Blackadder, for me socks are like sex. Tons of it about and I never seem to get any.

My Photos:
https://imgur.com/a/80hiRdm