Hopefully you can respect the women that you are with whoever they are. If that means you only have sex after marriage while fully clothed in missionary position before 8:30pm on alternate weekends....so be it.
Some of is enjoy a wider range of sexual activities than you do. I do believe that whatever you do, you should care about the feelings of the other people involved.
By the way, I have worn a thong (fairly recently). My girlfriend requested ot as part of sexual play. The "ass floss" felt a little ridiculous, and not exactly comfortable. My girlfriend showed her appreciation in the most wonderful of ways.