Don't be surprised... @macdaddi can affirm, Hotels are very strict with visitors. I've always booked a room for 2 even though I travel alone, even so I've had some try to charge an extra guest fee, to which I've told them to just register him.
The Hampton Inn Medellin refused a Venezuelan guy because he didn't have his VZA passport or a Colombian ID.... we had to go to a sex motel. The Airbnb I rented the next trip, they let him in with his VZA id....
I'm ok with taking, registering ID's... even in places like Thailand where the risk is lower. But Colombia doesn't play around and if you room is for 2 and you invite someone, be prepared to pay or stand firm that they're visiting and not staying overnight,,,,