True, I’m going by the novus ordo.  Is it valid?  I’m not the Pope.  (and doubt the current occupant is, either!)  In some situation under pre-V2 and even pre-1955, a person could get a dispensation that could even his entire household. 
I’ll leave the research to you, but I’m very confident of this. 
Pardon the indelicacy, but our entire family got a dispensation from an SSPX priest. Our Dad, head of the household, had to do the preparation for a medical procedure on a Friday.  It involved the drinking of large quantities of gelatin based liquid!  (For those who don’t know, gelatin is derived from bone marrow. You can buy vegetable based gelatin in the supermarket, but the medical product offered no choice other than lemon-lime or orange flavor!) 
Of course, there was no need for anyone else to use the dispensation.  Poor Dad was limited to his choice of jello or clear broth. 

I've got probably the very same procedure coming up in a couple of weeks, and know what is required.

As to gelatin, Jone says this:




If you can't detect the taste of meat in it, then it's no longer considered meat.  I have used rendered bacon fat for cooking on Fridays, and I cannot detect any bacon taste in it.  I also had some canned turnip greens that supposedly had been prepared with bacon fat, but I couldn't taste that either, so I went ahead and had them on a Friday, following what Jone says.

The way I usually explain it to Protestants in a way they can understand and respect (and hopefully push off their list of anti Catholic grievances) goes like this:
Our Lord sacrificed Himself in the flesh on Good Friday, so in thanksgiving, praise, and reparation, we sacrifice eating of flesh meat every Friday.  It's a small token of our love for Jesus.

As far as you paying for the meal, if I did the same, it would have been in the vein of feeding the hungry, hospitality and generosity. I don't think your action condoned anything, especially if Friday abstinence is only binding on Catholic and was nowhere on their radar