I'm currently renting my father's home from him while we work on renovations and clearing out 30 years of possessions. It became unsafe for him when he started tripping over the doorways which are also not wide enough for his walker, especially in the bathroom. I moved him to an apartment in a retirement community that includes two meals a day plus once a week housekeeping, and all utilities, not far from his home so he could still use the same bank, grocery, dry cleaners, etc because he still drives. Whenever he runs errands, he insists on driving by the house even though it's not really on his way. Today I get a phone call from him asking why are you home? I moved here to be closer to him, help take care of him when he's not well and just in general being more available to help. My mother died 5 years ago. I left a beautiful home and flourishing career to relocate. I'm 57 years old and have a regular boyfriend. I haven't checked in with him for about 40 years! Can I get some privacy please?
I don't suspect his intent is to stalk you.
Be pleasant. Answer his inquiries if you happen to feel like it, or give a silly response. If things escalate and gentle responses aren't working, you can resort to "Dad, you seem to forget I'm 57 years old and can make decisions without your input."
But start with, "I'm home today because it is my day off and I'm using it to work on clearing the guest bedroom."
"Well Dad, I didn't get fired if that is what you are worried about! I'll have enough money to pay you this month's rent."
"Next time you are in the neighborhood and notice that I'm home, stop in and I'll show you the progress I have made. If I have time we can go out for ice cream."
Assume that he is not stalking you. Only ask him to stop if more gentle measures don't work.
That said, I do feel your pain. I started staying with my mom in order to provide care, and in the beginning, I really hated having to tell her where I'm going or where I've been! I haven't even lived in the same town with her since I was 15, so....
My mom doesn't respond very well to the answer, "Out." But I did it anyway, because I'm 49 and I refuse to be accountable for my whereabouts.
If your dad isn't responding to gentleness, I think it's okay to say, "We've had this discussion several times, dad, and you know it's my own private business what I'm up to." And be a broken record about it.