I've seen one guy disappear indoors with two girls before, and the explanation has always been that the second guy is really really slow...this time however

When I opened the game there twere three girls standing together, and one guy. All three girls turned to go indoors, and the man followed them. As soon as they got indoors one of the trainee builders decided to "fix" the loveshack, and squatted down outside, apparently to fix the door frame. I continued to watch, thinking the other men might be on the way, and after several minutes searched the islend for a really slow guy going indoors. I never found anyone else headed that way.

These villager sare twisted lil people.