Standing in the corner at the start is not a bad way to do it. Let the other guys pile in first and then step forward at your leisure.
Some do's & don'ts:
Make sure you have fee ready as soon as you enter the door.
Get undressed & put your clothes in a neat pile preferably away from the action.
Don't hog any of the girls, remember there are other guys in the room who would like some of the action too.
Don't push in, wait your turn
Do make sure there is a condom close to hand, remember if you're having a BJ and then decide on FS, while you go to the other side of the room for a condom someone will probably take your place.
Do be respectful of the girls, it you put your hand somewhere & she pushed it away then don't move it back.
Do make sure you are clean at the start, if you are coming straight from work it may be an idea to ask the girls if you can arrive a little early to shower.
If the girls stop for a rest then do wait for the signal to resume playing
Probably plenty of others I've forgotten, above all have a good time and don't be embarassed if your not Brad Pitt - none of the others will be either and they won't be looking at you anyway.
Oh and btw see you there
