Yes I do find it weird but a lot of people do it, particularly when they get older and are lonely. My cousin did the same and is regretting it now as she gambles all his money and leaves him to look after her sons who are fast becoming criminals!
While you may find it strange it's probably best not to day that to him.
Only you can decide of course, but feeling sorry for him is not in my opinion a good reason to carry on being hurt yourself (been there, done that, didn't get any better)
You do have to think of yourself first. perhaps you could talk to him as annie suggested, great advice there.