Afternoon aggression?

[BullyMomFL]

Hi!
I have a two year old male bully who lately is showing some pretty aggressive behavior. It always happens in the late afternoon, and he will go after my boyfriend and another male friend with little or no warning. He is usually a very sweet and calm dog and will snuggle with both men any other time...is this just behavioral or could it be a medical issue?
Help!

 

[LisaMarie]

How old is he? Has he been neuter?

 

[KMARINO]

Maybe he is bored??? Perhaps trying to excercise him in the afternoon, with playing fetch or a walk to burn off some of the pent up energy?