Honestly, I wouldn't be able to stand to even look at my partner if he said such disgraceful things after one of his friends sexually assaulted me.
OP, your 'DP' is no partner at all, and a disgusting excuse for a man. You deserve and should choose better for yourself than a victim-blaming rape-apologist.
"...well I said to leave and to not have one more drink..."
In other words:
For the 'high crime' of your wanting to stay at a party, or socialising where there is alcohol - or perhaps for not leaving when 'DP' told you to - you deserve to be sexually assaulted by DP's friends whenever they feel like getting handsy.
When this happens, you should not expect him to be outraged on your behalf.
You should expect him to defend and excuse his creep friends whilst blaming you.
"...what do you expect he's steaming..."
"...he's annoyed because earlier in the night another of his friends was joking about us all having a foursome and I joked along saying yeah count me in. It was obvious that it was a joke..."
Wow.
So:
A. When one of 'DP's' friends has consumed alcohol, he is neither wrong, nor responsible for sexually violating you/women.
When one of his friends does sexually violate you/women, your 'DP' will immediately excuse and defend them, then attack and blame you or any other woman who dares voice her discomfort, distress or anger at being sexually violated.
But:
B. When a woman has consumed alcohol, 'DP' considers her both wrong and responsible when she briefly and laughingly responds to a bawdy but obvious joke made by one of his friends.
'Wrong' in that 'DP' considers himself to be justified in maintaining his annoyance at her obviously joking and harmless behaviour, even many hours later.
'Responsible' in that he actually points to her participation in that obvious joke with one person hours earlier in the evening as a legitimate fucking reason to blame her for 'instigating' her own sexual assault by a completely different person and hours later.
"...it’s hardly the time to be getting all #metoo about it..."
GMAFB.
"Now, ladies, do settle down and get back into your box and for goodness' sake, don't make one of those tedious scenes...
It's just another man who feels entitled to grope and sexually assault a woman without invitation or consent and another man who excuses him and blames her... That's all!
Nothing to get all (shudder) feminist about!"