AIO-I 36F found a text between my husband 37m and my cousin 38f that isn’t settling right

Repost to include convo* I 36 F found a text in my husband’s 37 M phone with my cousin 38 F that COULD be interpreted as flirtatious. Should I address it with the cousin? Or let it go? Been with husband for 10+ years. Convo was initiated by my cousin. First time I know of anything like it happening. I’ve already asked my husband about it and he said it was random and he didn’t take it as flirtatious. BUT it’s not sitting right with me. Worth mentioning that in person we’re (Me, my husband, cousin and her husband) all like this. But with our spouses present. But we have a group text that we use to communicate. We don’t normally communicate outside of it to each others spouse. Her husband has texted me about gift ideas for her. I text my cousin. My husband texts her husband. That’s been the extent.