Search Results: ex nervous around me

Once upon a time a woman named Kathryn was in the early stages of dating and sleeping with Antwan. She had an ex boyfriend named Jim that she openly stated was a "really good friend of hers". Kathryn stated that she texts him before going to his local wellness store to see if he is there and have items ready for pick up.

It is the Christmas holiday. Antwan is dating Kathryn but doesn't know Jim. They both have a mutual friend. A picture was put on facebook of their mutual friend in the first week of December. It was posted by Jim. Kathryn liked this picture. The caption of the picture said:

"Will miss my buddy. Looking forward to my trip to Mexico next week."

It is the holidays. Everyone seems to be traveling to places for Christmas. Kathryn has an older brother who lives in Mexico City. Antwan has been dating her for 3 weeks. She seems flustered and disoriented packing. They have sex. The next day she seems nervous. She kisses Antwan goodbye and leaves for Mexico.

While in Mexico she texts Antwan throughout the day. All day every day. Constant pictures. She is very into Antwan. But at one point she says she misses him but also loves Mexico so much she wants to return in the Summer for 3 months.

A few months go by. Kathryn texting her ex boyfriend Jim comes up. Antwan has been dating her for 2 months now. In bed he asks her why she needs to text this ex boyfriend to see if he is working at the store he owns. Kathryn says he is just a friend.

She says, "It's no big deal. He helped drop off my brother's Christmas gift."
Antwan says, "In Mexico?"
Kathryn corrects Antwan, "No. He prepared the gift items in his store before I left for me."

Wasn't Jim in Mexico at that point? Antwan then asks why they broke up. Kathryn wraps her arms around her stomach in bed and becomes annoyed saying, "I just don't like him like that. We didn't have good sexual chemistry."

Did Kathryn meet up with her ex in Mexico?

I asked a question about something similar to this before.

A while ago she told me her and her best friend used to have history and have “fucked around before” (she said didn’t they didn’t have sex but he’s grabbed her boobs and I’m assuming made out or whatever)

and at first I was a little nervous that she’s best friends with a dude she’s done shit with before. But I trust her, and I decided I was being a little insecure due to being cheated on in my last relationship. So I forgot about it.

Today I was walking home with her and we were going back and forth with the little roasts/jokes we do. (We’re both sarcastic people, we’ll poke fun at each other sometimes)
And one it her responses to me was something along the lines of “Okay, I’ll kiss my best friend in front of you”

she was joking around but it was just a joke that was too real for me considering I already had concerns about her being attracted him..

And it was very out of nowhere. I don’t remember what I said but I remember not understanding the correlation of why she would bring him up.

I didn’t get mad at her or anything because I felt it was just something stupid I was overthinking about.
I just get nervous because my ex used to make “jokes” about having a second boyfriend and it turned out to be true...
So am I ignoring red flags or just being insecure?