Why would someone possibly have holiday weekend plans?

Saturday morning c. 9:30am, my parents call.

Mom: Were you asleep?
A.: No.
Mom: Did you just wake up?
A.: No.
[This is only blogworthy for the logic I believe to be behind it: I wanted to sleep in the weekend I got in from Australia, leading my mother to be surprised that I'm up at 9:30am on a Saturday. Just a possibility.)

Mom: What time are you coming next week?
A.: A little before 11am on Saturday... which reminds me: did you have any plans that involve me for next weekend, because I was thinking of heading out to Northampton to visit friends...
Mom: Northampton?
A.: Yes.
Mom: Is that where Smith is?
A.: Yes... I figure it will be a busy weekend for buses so I wanted to look now...
Mom: Oh! I have an idea! Irina [family friend who lives in Berkshires] is always inviting us over for the weekend. We can drop you off in Northampton.
A.: Oh, great! That would be perfect. Let me know when you've confirmed with her.
Mom: No need- she's always inviting us, and she needs herring. Wait, did you want to spend more than a few hours there?
A.: Yes, preferably.
Mom: Why?
A.: ???

[call waiting; I have to take it, I'm expecting a call from a friend with whom I have plans to go hiking today.]

A.: Mom, I have to go, I'll call you back but in the meantime could you confirm with Irina so I can go ahead with my plans?
Mom: Oh, we can go to this place...
A.: I HAVE TO GO. I'LL CALL YOU BACK.

Less than two hours later:

A.: So have you spoken to Irina?
Mom: Why would I speak to Irina?
A.: To confirm plans for next weekend.
Mom: Oh, well she's always inviting us over, I don't need to do that.
A.: She may have plans.
Mom: Why would she have plans?
A.: It's a holiday weekend and she has family and other friends.
Mom: I don't think she has other plans.
A.: Well can you please check?
Mom: I don't need to check. She's always inviting us, and she needs herring. How long do you want to be in Northampton? Overnight?
A.: Preferably, yes. [I don't see how her need for herring precludes the possibility of her having other holiday weekend plans, including other guests].
Mom: Why don't you want to stay overnight at Irina's?
A.: I just want to spend more time in Northampton.
Mom: This doesn't need to be decided now.
A.: It does if I need to look for bus tickets!
Mom: Don't worry, Irina won't have other plans. I don't have time for this right now.
A.: Okay, I'm just saying I would feel better if you actually asked her and confirmed the plans.
Mom: Okay, later, bye.
A.: Bye.