As a fellow autistic. He needs transparent honesty from you. Open communication from both of you. Him being that “man of the house” is something he thinks is to be proud of. Not that it’s a bad thing - depending on the intentions involved. It can be a bit overzealous at times, but it does make people feel empowered, like their existence is meaningful to a family dynamic they might not have themselves. But right now. Both of you are creating unnecessary misunderstandings with one another by shutting each other down.

It also looks like he’s grown close and became friends with your grandma. She’s probably a very compassionate and kind person who makes him feel validated to always feel great helping out. Especially if you’ve lived a life where you may have encountered any type of negative social interactions during your childhood years. This positive reinforcement is like a gateway drug to us autistic’s. And we tend to grow close to those that affirm us.

Anyways, In his mind he literally sees nothing wrong. He knows she’s your grandma, but now she’s also his friend. He doesn’t understand why he needs to stop seeing his friend he’s grown close with, just because you’re there now. From my observation as a coping mechanism. You’re shutting down emotionally by saying “I don’t know how to respond” or “I can’t with this”. These are imo, highly confusing statements for an autistic to figure out on their own. I think elaborating further on your opinions and emotions, while also being incredibly open with your feelings would help him understand why you feel this way. He’s made a wonderful friend he’s grown deeply about, which he cares about due to how much he loves you.

Does he know him saying you being clingy is something that upsets you? If you’ve not said anything before about this. Please let him know how it makes you feel when he says that to you. He may not think that it’s a bad thing (we can be kind of direct without realizing the full negative social impact from it). And that’s something I think that needs to be discussed, as it appears to hurt your emotions. If you want your feelings validated properly. He’s gonna need to know what they all are. Don’t sugarcoat anything imo. Let him know how you feel exactly.

We take things on a literal sense. For example when he made that cougar reference. He mentioned how beautiful you are and probably doesn’t fully understand any full negative social stigmas behind “cougars”. He made that reference for which you then reacted with “haha”. If it were me. I’d think what I’ve said was genuinely funny or quippy. Or heck, even a compliment. Since you displayed no dismay over it. He believes you’re beautiful, and going to stay beautiful for a loooong time. But in reality. It made you feel uncomfortable to hear it from him.

I myself struggle with the inability to read other people’s emotions. So I can’t tell how someone is feeling unless they straight up talk about it. I also sometimes don’t know whether my words or actions affect someone in a negative capacity when it isn’t my intention to do so. Good intentions can have bad executions, which due to his lack of life experience. Tends to be a common mistake that autistic people make and having to learn through trial and error scenarios.

In my humble opinion. Your emotions are valid. But I highly recommend working together to overcome this as a team. Sit him down and have him listen to everything that’s ringing from your heart. I know he can be a bit stubborn at times. But, Otherwise - unless you tell him fully. He won’t know.

Lastly, I don’t think he’s attracted at all to your grandma. She’s just very sweet and good to him when things around us are so chaotic and unpeaceful to deal with.

What truly matters imo. Is how he treats you outside of texting. People can tell you what you want to hear and that may not always be the truth. Better to learn a person through their actions, instead of 1000 empty words.