My sister is visiting us, here in Costa Rica, with her two daughters:  Mandy, who is Martin’s age, and Julie, who is about to turn two years old.

Sunday we took a day trip to a nearby beach town. When we arrived, the kids got fruit smoothies. Then we hit the beach. The waves were pretty strong. We adults (my sister, my brother Eddie, and I) took turns going into the surf with the kids. I try to get Martin as much salt-water time as possible. I consider the ocean a health spa.

Martin had already had several solid days with Mandy. She attended camp with him. The two of them fussed and played for hours each afternoon. They put together evening concerts: Mandy wrote an emcee script for Martin to perform, and then, using five-pound dumbbells for microphones, the two sang Uptown Funk!, A Million Dreams, even a jazzy version of Happy Birthday to send to Adrian, who’s in New York. The songs were accompanied by the kids’ original choreography, which resembled running crisscross while high-fiving each other at each pass.

And now, Sunday, everyone was having a great time, as far as I could tell, even if Martin did start to get anxious as lunchtime neared.

We left the beach to walk to an outdoor fresh-preparation food stand (everything gluten- and dairy-free! pura vida!). Along the way we stopped at a souvenir shop, where Martin selected an inexpensive carved frog. I spoke to the proprietor in Spanish. Martin refused to look at the man. Instead he put his face near mine and whispered, “Mommy, pretend you don’t know a word of English!” Martin’s picked up an odd obsession lately: He tries to dictate who can speak which languages, and when. He even manages to impart his angst into the topic. If he finds out we are going out to dinner, he demands to know in advance whether I plan to speak Spanish or English to the waiter and tells me to guess whether he plans to do the same. In the souvenir shop, I said, “Martin, that’s silly. He can tell I have a North American accent. Why don’t you say hi?” The proprietor then greeted Martin, in Spanish, and asked how he was doing. Martin turned away as if he hadn’t heard. Covering, I apologized and said that my son does speak Spanish but is shy about doing so.

As soon as Martin and I were back on the sidewalk—Mandy and the others had wandered to another shop—Martin started to meltdown. His meltdowns are so infrequent these days that I don’t anticipate them like I used to, and this one caught me of guard. Martin asked, “Why did you do that? Why did you tell him I speak Spanish?” His words quickened as he said, “Why did you try to make me say hi? I didn’t want to do that. Why are you so mean? You’re the meanest mom in the whole world.” He was crying as he descended into nonsensical opposite-talk: “I hate you. I don’t love you. I wish you weren’t my mom. I don’t speak English anymore. I’m never speaking English again. New rule: I have to talk to everyone we meet!” He thrust his jaw forward (that old trick again!), clenched his fists, and motioned as if to punch me, though he did not make contact. (He never does, thank heavens.)

I stood by him and let the meltdown run its course. When the opposite-talk subsided, I tested the waters. “Martin, were those the things you really wanted to say?”

Still not in control, he answered, “Sorry, Mommy. I didn’t mean it. I did mean it! I hate you!” He air-punched again, then hugged me, sobbing.

Mandy approached, accompanied by my sister and Julie. Mandy asked, “Why is Martin crying?” Her question pained me, for two reasons. First, the obvious reason: Especially in the moment, I have no effective means to convey to a nine-year-old that her cousin is crying because anxiety has been collecting inside him until a random, almost undetectable social pressure knocked him into a netherworld of confusion. Second, the less obvious, more painful reason: In visits past, Mandy tended to ask mequestions about Martin. “Does Martin like watermelon?” “What time does Martin get up?” I would have to remind her that she could ask Martin, even if he didn’t always answer immediately. This visit, until the meltdown, had been different. Mandy had been asking all her Martin questions—even questions about food allergies and what he can eat—to Martin, and he’d been answering. As he returned to meltdown mode, however, she stopped relying on his ability to speak for himself.

I said, “He’s having a tough time right now. Why don’t we walk to lunch?”

Cheerfully, my sister said, “Great idea! Let’s walk.”

We continued to the lunch joint, Mandy casting suspicious glances at Martin as he tried to get himself under control. By the time we sat at a picnic table, Martin had stopped crying enough to manipulate me. He said, “I think what would help me calm down is your iPhone.”

Adrian and I don’t usually allow screen-time at meals. Nevertheless, I gave in. I wanted to distract Martin from whatever was bothering him before Mandy witnessed any additional meltdown.

A day trip with his favorite cousin, to a beach he knows and enjoys, with the promise of lunch at a food stand he likes, and then, pow!, a meltdown. The frustration! Sometimes it feels like no much Martin’s health and behavior improve, the remnants of autism hide inside him, ready to interrupt paradise with their ugly ways.

My survival tactic is to remember to look for the silver lining. Sunday, allowing Martin to play with the iPhone did the trick. By the time our food arrived (25 long minutes later, pura vida), Martin was ready for limited participation in lunchtime discussion about the waves and fun we’d had in the ocean. On the drive home, strapped into the third row of our SUV, he beatboxed with Mandy. Almost as soon as we arrived back at our rental house, a brother and sister showed up for a play date (these arrangements were Mandy’s doing), and Martin participated decently. Mostly he followed the brother around spouting Minecraft strategies—but hey, that’s a form of socializing.

Martin melted down.

He bounced back.

I take what I can get.

Martin and Mandy, in the waves.