Well I'm a FReeper female Army vet. They were having fun. They didn't hurt her in any way -- she was laughing the entire time. You may not understand if you've never been in the military, but things like this build morale and unit cohesion. There also seems to be high level of trust. From watching the video, she trusts these guys completely. She knows they won't hurt her or take advantage in any way. She probably also knows they would protect her with their life if need be.
Try unclenching your butt cheeks a little...you won't be so uncomfortable sitting at home in your nice cushy chair while criticizing those in harm's way who take a little time to have some fun.
Anyone who would post "Moods of a Woman" on their home page doesn't know what it's like to lead.