Sex advice with Suzi Godson: 'He has no right to share sexual confidences in public'
You are not wrong. Your partner is. He is broadcasting what should be a private exchange to a public audience without any consideration for the impact that it is having on you and that makes me feel very cross on your behalf. Boasting about your sex life is not “just banter” if you find it embarrassing, and telling someone who feels mortified to “relax” is insensitive to the point of insult, particularly when directed towards someone you love.
No matter what your partner says, sex is a universally private experience, and generally, sexual intercourse takes place behind closed doors.

