Should I be worried that my partner is on vacation with a woman I don't know about

 

Should I be worried that my partner is on vacation with a woman I don't know about

Should I be worried that my partner is on vacation with a woman I don't know about

EDIT: I just found out it was a girl he left me for and tried to date about a year ago! But according to him, there's no feelings on either side anymore so it's okay. Haha

My (27F) partner (30M) is on vacation with a woman he keeps calling a friend, but I've never heard him talk about this friend other than referring to her as "his friend". I had no idea it was another woman until I asked him who he was with.

He said he's there with his friend, his friend's gf, this woman I know nothing about other than that it's their mutual friend, and allegedly her family as well.

I have a really bad feeling about this since he didn't tell me anything about this woman and has kept referring to her as a gender neutral friend. I feel like he's hiding something from me.

Tldr; partner is on vacation with his friend, his friend's girlfriend, and a "friend" I know nothing about, other than just now finding out she's a woman. He has been avoiding telling me her gender and has been only referring to her as "their friend". Am I being crazy jealous or is this suspicious?