I remember during events my Mom was always up and down running all over the place taking care of things. She was a great hostess, but mostly I believe she preferred doing things to chit chat, so she spend her time up and doing. She chatted, but not too long.

This might not be your style, but could work in this situation. Keep the girls around the "Prep area". While there, always be fixing some sort of snack. Don't bring them out all at once. Bring them out one at a time and be insistent that they are guests and they should sit down because "You know how hard you work". Do all the prep during commercials, and when dropping off the food to the TV room, linger, watch, and take your good sweet time getting back. Maybe bring a piece of trash back with you to give off the "I was cleaning" vibe. Repeat when the next commercial break comes up. Once you run out of food, use trash bags to go in and out. Give off a busy vibe while lingering around football. After about an hour of this your guests will get it and admire you for being such a clean and active host.

Or, you could just be honest and pull up a seat on the couch inviting the girls to do the same.