I've been very cautious so far and finally found my way to being willing to open myself up to a relationship at all. Now my boyfriend's father passed away and he abruptly moved in with his mom to take care of her. I am a business owner and work very long hours. Now for us to spend time together I leave work late, run by my house to just be sure it's there and then go to his (Mom's) place. I don't want to be selfish but it's getting kind of old.
If you feel this gentleman is "the one", please give the relationship some time, and give him some breathing room. He has a lot to figure out and challenges ahead. Do not put any demands on him.
Ask him what you can do to help. He would greatly appreciate that. And be thankful he is the type of man to wishes to help out his Mom. That would mean he would be a great caregiver if there is a time in the future when you need help.
And also think, what if the tables were turned, and you needed to take care of a parent.
But you don't say how long the relationship has been going, when your b/f's father passed away, or what ages any of the involved parties are; and not to pry but we also, of course, have no idea what left you feeling apparently "once bitten" about relationships beforehand.
So all in all...
The main question is how long ago the father passed away. If it was less than - what would we say, three months? Six months? A year? - and if the mother was fond of him, and especially if she has other health issues too, then it could be either that you'll need more stamina or that you should agree to part before there are too many hard feelings.
Does he work? Who takes care of his mother while he is out of the house (if she needs care)? Why can't he get away for a "date" at least some nights? If she needs care, is he working toward arranging that for her, or does he plan to do this the rest of her life?
As others have said, stepping in to help a parent after a traumatic loss is admirable. It is the long-term plans that would be most important to your relationship. Can you tell us more about the situation? How is his mother's health, for example?