Someone is sexually frustrated tonight..... Yes, delicious part of foreplay Will it make you hot to have your balls licked? (BTW - Perineum is the skin between your anus and testicles. Some men find it very enjoyable and say it can intensify "O" if rubbed while they cum.)
Yes, I do believe most know this is just harmless flirting, teasing however you'd like to term it as. There are always a few that will take it a step beyond that; Not my business, Not my thing. We are all adults with independent minds and thoughts.
I agree with Ready, some things are left to the imagination. I think if you do experiment with others sexually for a three some or whatever, you better take a reality check just to make sure your marriage can withstand the fall out afterwords.