Is it rude for a friend to stop by, uninvited, and stay if you are obviously otherwise occupied?

My boyfriend has a male friend that lives in an apartment above him. I think the friend takes advantage of my boyfriend's kindness. Last night, the friend calls my boyfriend at 10 pm and my boyfriend does not answer. 5 minutes later, the friend shows up at the door with beer and wants to know if the Monday night football game is on (the friend does not get ESPN on his tv). My boyfriend says yes and the friend proceeds to enter the apartment and sit down in a chair in front of the TV. My boyfriend and I were having a private conversation on the phone so he went into his bedroom where he stayed, talking to me, until the game was over. The friend did not leave when he realized my boyfriend was not going to watch the game with him. In fact, he didn't leave until the game was over. Shouldn't the friend take a hint and leave? Or not even show up unless invited? Also, shouldn't my boyfriend just tell the friend he isn't up for watching the game instead of worrying about not being hospitable? Similar situations to this happens often.