i dont know what these boxer briefs are....are they like sloggi's
anyhow boxers are what i wear as more room, but they can get inconvinent if tight round the legs, limiting motion. plus you always gotta watch it in the changing room with them..
boxer briefs are the shit!! they combine the roominess of boxers, but without the bagginess that gets in the way sometimes. they are looser than briefs, but tighter than boxers. your g/f will like the way they fit you, and you won't scream "gay" to yourself.
of course, SOMETIMES no underwear is the way to go!!! that extra layer of fabric does get in the way, when the action gets hot'n heavy sometimes!!