Will need to provide context to explain the situation

As a little precursor, I have Aspergers with one thing being for me that too much socialising can really stress me out. I go to uni with a friend I have who I've known for around 4 years at this point. We get on quite well, although there is a very strange habit that they have done over said time. It feels like they synchronise their schedule so that we happen to do the same actions around about the same time. Some of these make complete sense to me like same route home and going for lunch together, which im completely fine with and am happy with.

Where the issue in this lies for me is that this also applies to things such as going to the toilet. As soon as I say that I'm going to the toilet, they go to the toilet as well. I wouldn't really mind this so much if it wasn't for the fact this happens every single time without fail when we're together. This also applies to situations where I'm really wanting to spend time alone due to social burnout and I really just want time alone, but they change their route and time leaving to follow the same path as me. Its socially exhausting and tend to give more of a headache than anything. I try to at least hear them out since they are my friend and I just try to put up with it, although the talking becomes so one sided with the topics that I'm genuinely not interested in, its just them speaking on and on and on while I don't really say anything, due to a mix of not getting a chance to get a word in and at the time really not wanting to socialise.

I do feel bad that sometimes I just completely shut down and basically nod to whatever is being said, not really listening but with them talking for hours each day to me already I just want time to hear my own thoughts and just to be able to be able to not have to socialise all the time which is something that freaks me out majorly if I get overloaded.

Leading back to the question at hand though, I haven't said anything as of yet because I wanted to see what people here thought. I'll just note that despite what I've said, the person in question I do really like. They're a really cool person besides some of the odd synchronised schedule with whenever I seem to go somewhere like the bathroom. There's only so many times I can handle them talking on about something so much while I'm sitting on the toilet, while they're right there waiting for me. I don't really want to come across as an arse with this although its something thats just really been on my mind for a while.

TLDR: I'm friends with someone, they talk to me ALOT, attempted conversation areas can be very unnerving, (such as bathroom/restrooms while im in a stall),conversations can become very one-sided at times, I struggle to handle all the conversations they want to have which causes me to burn out from talking, wanting to ask if they could try not to talk to me constantly or synchronise their schedules all the time to that we're on the same path).
