My closest friend is giving me the silent treatment. What do I do?

I have a guy friend, we are pretty close. He has admitted he has feelings for me, but i have told him that there is a possibility i may get with my ex in the future. I wanted to be honest with him, so he has no expectations. He chose to remain my friend. We text everyday, and occasionally call, he doesn't live close so we don't meet up often (when we do it is usually on my terms, otherwise he would be asking to see me every day). We have a tendency to argue, he can be quite manipulative sometimes (yes, i know i have my flaws too). Example, stating that i shouldn't go on holiday, if i do i better make sure i talk to him otherwise i obviously don't want to talk to him. Also, he makes endless assumptions about how i am feeling. I will tell him why i am upset for example, and he will start talking to himself going "that obviously isn't it, its probably this". This recent one has left me stumped. Two days ago i didn't really text him often, i sent him all of three texts that day. We spoke on the phone that night, and he was acting strangely, making comments like "you get everything the way you want it" - he was clearly irritated by something. After an hour he finally started talking about it. Claiming that there must be something wrong with me because i barely text him that day. I explained that it was just because i was busy. (He was aware that i was out that day, with my ex, and i know that is part of the reason he was upset, but he does get sulky with me if we haven't text often one day, my ex presence just didn't help). He said that other days i have been busy but manage to text him so there must be something looming, something must of happened. To which i explained that i was just busier than other days, that our texting frequency will not remain the same for every day. He kept questioning it, starting that we hadn't spoken for 12 to 15 hours (i was asleep for around 9 and half of them hours) and was wondering why i was getting irritated. He finally said, "do you not think i should know about your life" (i told him last week, that i am very open with him), and that if this is how i behave and if this is natural for me then fine, that he isn't complaining, and clearly i do not want to talk to him about it. I simply replied "ok" because the entire situation had escalated. And he just thank you and hung up. He hasn't messaged me for an entire day, which is unlike him. I would of course text him, i never have an issue with that. But i am not sure if i should, i do not want to feed into this. It was simply one day i had only text him three times, i hadn't disappeared on him, and i agreed to have a phone call that night. What should i do now? Should i text him? He has a rather messy past, and i know that explains a lot of his behaviour, and when he isn't acting this way, he is a great friend. Thank you for reading.

He is upset because he clearly has feelings for you but you are with your ex trying to get back with him. It has only been one day but he needs to be more distant from you. This relationship is only hurting him. You two need some time apart until he can stop being hurt by your involvement with your ex.