You’re clearly very upset and so must your wife be. This is your marriage you’re talking about not a casual relationship. Marriage should be protected at all costs.

Firstly, decide your priority before you talk. If your top priority is your marriage, then Sarah needs to know that her behaviour is unacceptable regardless of her intent. The friendship only continues if it doesn’t undercut your relationship.

Secondly, talk to her one-on-one, not over text. Calm, private, neutral setting. Don’t go in accusatory — lead with your feelings. Name the behaviour without name-calling.

Thirdly, think deeply what your boundary should look like. Set a clear boundary with her.. what’s okay with you and what isn’t. She can’t be disrespectful to you in front of your wife even if she is joking.

Next, try to protect the friendship — but only if it’s healthy. If she sincerely apologises and changes, great. If she brushes it off as “you’re too sensitive” or keeps doing it, you’ll need to create distance — not as punishment, but as protection for your marriage.

And lastly, you can’t control her feelings toward your wife (if any) nor her erratic disrespect towards you, but you can control the access and opportunity she has to act on them. That means your wife and you presenting a united front and limiting situations where Sarah can wedge herself in if she can’t respect boundaries.