What Causes Pain In The Calves After Standing For Long Time?

If I stand for a period of time to talk to friends or just stand in line, I get antsy and have to keep moving because my calves start aching and my feet start hurting, they also feel like they are swelling within my shoes (but arent), My boyfriend can stand for 30 mins and talk away, 10 mins into a conversation it feels like I need to move... or just scream.