Aitah for rejecting my friends request to have an open relationship with my husband?

The I (30F) have been married to my husband (32M) for five years. We have 2 beautiful kids (5m and 6f) and have a very strong relationship and are happy together. Recently, my “friend” Lisa (29F) confided in me that she has developed feelings for my husband. She said that she finds him attractive and admires our relationship, and she asked if we would consider having an open relationship so she could be with him too.

I was shocked and told her no, explaining that my husband and I are committed to each other and that we are not interested in an open relationship. Lisa got upset and accused me of being selfish and closed-minded. She argued that modern relationships should be flexible and that I was denying her happiness.

Since then, Lisa has been distant and has been spreading rumors in our friend group, suggesting that I am overly possessive and controlling. This has caused a lot of tension, and some of our mutual friends are now taking sides. My husband is supportive of my decision, but I feel guilty for the drama it has caused.

So, AITA for rejecting my friend’s request to have an open relationship with my husband?

Edit: This attracted a lot more attention very fast then I thought it would, I’ve read most of your comments and I think tomorrow I will talk to the whole friend group about it and I’ll update after.