I have been on my MAP for about 5 months. I have made huge improvements in myself, including lifting, grooming, being a socially outgoing person and leading my wife.

When I found MRP, my relationship was logistically functional, never a dead-bedroom and we had sex 2-4 times a week, with a very few sexless weeks in between. While I was on my MAP, things had come to a point where my relationship was not even logistically functional. It had gotten worse to that point. I kept on my MAP, and started leading her. After many mini main events, my relationship with my wife improved dramatically.
I got the logistically functional relationship back, the quality of sex improved and she became a sweet woman.
I was having the kinkiest sex and role-play became a huge part of it, because of MRP.

Just yesterday, I failed, pretty badly.
This was my 1st loss of frame after finding MRP 5 months back.
I realized later that it was day 8/9 of her cycle, and that ovulation shit testing/high sex drive might actually start on day 8. I always assumed it to start on day 10.

We had my friends come over to our place for a house party.
I had cooked food for everyone, since wife was out in the afternoon for shopping with SIL.
SIL and wife came back home to the start of the party.

After drinks, I got the plates of food(we do not necessarily eat on a dining table in our culture). No excuse, but I was drunk and forgot to ask SIL if she wanted to eat and did not offer her a plate. Wife noticed this.

Wife was in the kitchen, and I went to the kitchen to get something.
What I saw was the craziest, meanest bitch I have ever seen, almost yelling, with friends in the house.

W: "How the fuck can you forget to ask my sister for food? You are just too much into people-pleasing and licking your friends' asses, offering them food, making sure everyone is comfortable. But you can't ask my sister?"

M: "Oh, I am sorry. I should have offered a plate to your sister. How can I forget?"
W:"Don't fucking say anything now. If you cared for your woman and her family, you would atleast offer food. But it seems we are secondary to you."
M:"No. That's not true."
By now, we both knew some of our friends might have heard this conversation.
W:" Every time your friends are here, we get into some sort of argument and I come out as the bitch in the end, in people's eyes. I am never ever going to hangout with your friends again."

Now here is where I failed. I felt very guilty for not offering a plate to SIL.
I went out into the group and apologized SIL for not giving her a plate, in front of everyone.
I should have had a private conversation with her. Huge DLV in front of everyone present and wife.

Back in the kitchen...
W:"Are you a fucking stupid idiot, apologising to her in front of everyone? Do you not have common sense? Why the fuck are you creating a drama?"[All while pushing me away and being aggressive.]
M:"Yes. I should have just asked sister to come in and had a private conversation with her."[While holding her hands in my embrace so as to not let her move me with her aggression.]
W:"Don't you dare touch me or hold me like that. You are fucking things up and it all comes on my head. Leave me."
I leave her and she slaps me. Not a very hard one but yes it was out of anger. This has never happened before in our entire relationship. I could see how low value I was in her eyes, still.

I didn't say a word after that.

How should I have handled this better?