Partner on holiday with a female friend!

Why did he lie?
Because he wanted to go but knew you wouldn’t be happy and his feelings trump yours
Is it reasonable to not want your partner to go away with another woman? It depends on the circumstances, the history of the relationship and your relationship.
Its totally reasonable to end the relationship due to hm lying to you.

My personal opinion:

Women are fully capable of being platonic friends with men. Men can be great company for friendships.
However, in my experience, across many men and many platonic friendships: the men are always sort of hoping for a shag. They'll accept being mates but given half a chance, they'd like it to progress to another level.
Then when it gets awkward, they're not always the super nice guys you thought they were. Not worth the hassle.

OP: taking the woman out of the equation altogether - he's a liar. To the bin with him.

Did you miss the part where he lied? If he had nothing to hide he wouldn't have done that. The 'low standards' are in relation to the lying not having friendships with people of the opposite sex.

A woman being a member of the friend group and staying in the apartment is a non issue. Him lying about it is though.

Depending on who the female friend was, I wouldn’t mind, but I would strongly object to the lying about it and concealing it. That’s a bright red flag.

This. It’s the lying that is the problem, and the reason why you did the right thing in dumping him.

Why did he lie? That would be the issue to me, not necessarily the woman.

Gosh, so many variables: the nature and background of your overall relationship, the nature and background of his friendship with the woman, the overall vibe of the other men going…

I mean, when I met dh there was a woman in their friendship group. To me, she posed no threat. She was always ‘one of the boys’ (and not remotely in a pick-me way, she is just very straightforward, quite ‘manly’ herself and has always got on with other men). She’s also a thoroughly decent woman with high moral standards and wouldn’t have dreamed of flirting with another woman’s boyfriend. So I would have zero problems with that. Dh and his friends are also among those rare species of decent men and in the decades I’ve known them, not one AFAIK has cheated with his partner.

Another woman, another man, and a different set of friends and rules… I’m not sure I’d be happy. The lying is unforgivable.

I think you're being unreasonable to even use the word 'allow'. Neither of you are children.

He lies when it's easier for him. Dump him.

Yanbu he lied. Why lie if it's all honest and above board?

Would the op have coped if he told the truth or be just as controlling?

Going on a group holiday with a friend that's a woman: fine. Lying about it not fine, IMO. But then again if you're someone who kicks off if he spends time with his friend who happens to be a woman maybe that's why he lied? Although it seems like he also doesn't think men and women can be friends, so.... this isn't really a way of seeing the world I understand lol

The fact he lied is the main issue.

It's the lying that would bother me more than the female friend going on the holiday as such. If he felt the need to lie, does that mean there's more to the friendship than he admits?

Dumping him was the right thing to do.

WTF!? So women and men in relationships who have friends who they like to spend time with of the opposite sex have no standards?

Group of mixed friends going on holiday together - not even a tiny issue, you're being ridiculous to object to this.

Partner lying about woman going on holidays with the lads - that's a problem.

Spot on, imo. No way I’d be ok with this - if he lied about it, he knows it’s not ok.

It's actually not, and this pass agg 'women with standards' is such a nasty dig. Women and men are allowed to mix, not everyone feels anyone with a vagina is a danger and that's ok.

Are you sure there are any of the guys there?

Meanwhile, in the real world, for women with standards, your boyfriend going on holiday with a female friend then lying about it is unacceptable.

It’s a mixed friendship group so it’s not just your partner and her. So I don’t personally see a problem but it’s obviously a problem for you. I’m guessing he wasn’t straight with you as he knew this would be your reaction, it wasn’t right of him to lie but I can understand why he did.
Do you think she’ll be having sex with all of the friends or just your partner? Do you generally have trust issues or just with him? Does he have a history of cheating on you or has that happened in a previous relationship?