Travel sex buddy ❌ Not a friend?

Hey girls. So when i was traveling in the Philippines i met this guy, from Manila. He is a common friend of my friends. So we were all hanging out for 4 nights straight. And on the 5th day there came this idea to travel to another nearby surfing city. It was just the 3 of us: the GUY, a friend of his, which ended up becoming my friend as well, and I.

We arrived pretty late and started drinking quite early. After the right amount of beer, i of course got drunk, and this GUY and I ended up having sex in the hotel room while his friend was left in the bar with some other travelers.

Anyway, the next day it was all good, traveled to another city. Again, hotel, sex etc. his friend slept in another room(no worries, no threesomes lol) . And since i was traveling solo, we agreed to meet up again, in one of my destinations by the end of my travels. We spent another 3 days(after not seeing each other for 3 weeks). It was the most relaxing time of my stay in the PH... he had to leave back for Manila a day earlier cause he had work the next day, but my flight was only the next evening. Upon my arrival he stayed with me in the hotel for that last night of my stay in the Philippines. Then i left...

We spent really great time together, talked about lots of personal stuff! At some point i thought we could even stay good friends even after i leave.... BUT... right after i left the Philippines, our communication pretty much stopped... he wouldnt text me anymore and barely respond to my messages....i mean im over it already, but still cant understand this logic... is this common for guys ? Travel+sex NOT equal friends? Its just too sad to realize that we could have stayed friends from the beginning without having all this... he is also planning to visit the country im currently residing in(china), though a different city. But was thinking of touristing in Beijing. Dunno how its gonna go... it will be only by the end of May...