She happened to let it slip that your turned on by sharing her while talking to her guy friend who immediately asked if that meant she was available for sex.
She confronts you about it as you see her bite her lip in anticipation that you are going to tell her to let him know that she is available if he wants to hook up with her.
This was a fun conversation with my wife. I knew of a few guys but didn’t think there were that many as we went to the same high school together. Then she started counting. The first 4-5 guys I wasn’t surprised, then 6-7-8-9-10. Yep 10 guys have seen her tits. She admitted “it didn’t take a lot of convincing for me to pull up my shirt and bra to show my tits. The interesting part, all 10 of these guys still live in same area as we do.
Let your wife have what she wants.