Licking your girlfriends back side?

Recently fooling around with my girlfriend together things got really hot and heavy I would tease her by using my finger on her backside which she loves but recently she found out how much she loves having a tong there I thought she was gonna break her own back from the O she had. How many men and women enjoy this? For you men if she is cleaned well it's not as bad as you may think at all and if she enjoys it she might wake up the neighbors (sorry guy upstairs) are you comfortable enough with your own bodies to explore this or do you stick to the old standby. Men do it! Women hang on for the ride ;)