OK, here's the back story...
2 weeks before our wedding, FI and I decided to have Engagement Pictures done (I know, kind of late in the game, but that's besides the point). Later that same day, FI was going to his Bachelor Party.
I personally invited my mother and MIL to engagement photos - I thought they'd both appreciate the opportunity to share such an important event with us. My mother accepted, MIL said she was busy and declined. Fine - no skin off my back - and we moved on.
Bachelor party time rolls around and afterwards, the guys decide to have a cookout / bonfire at one of the groomsman's houses. They decide to invite some of the women too (a little unconventional for a bachelor after-party, but it works for us). I'd also like to add that all invitees knew about the particulars of this after-party well in advance of the actual day.
Bachelor After-Party rolls around and MIL does not show (FIL does). Because MIL was too busy earlier in the day for engagement photos, FI and I assume that she is busy now too and think nothing of it. Everyone has a great time!
Fast forward to next day, and MIL confronts me crying, saying how disrespectful I am for not inviting her to the party when other women (FI's cousins, etc.) were. I politely try to point out that I was not in charge of the invites (that was all FI and groomsmen), but that I did understand why she was upset. I refrained from saying: "Well, you were too busy earlier in the day, so I thought you were too busy to attend the party" out of respect, and to avoid any further argument / resentment that may develop. I'd also like to add, later that same day she did apologize, but I felt like it was a half-hearted apology at best. I've since moved on, although it did aggravate me at the time.
Fast forward: FI and I got married and had a wonderful wedding and honeymoon. Two weeks after we were back from honeymoon, MIL and FIL came to town for dinner. They showed up unannounced and asked if we'd like to go to dinner. We politely accepted - but I had just finished a terribly busy week at work and was a little tired. I personally would have preferred to stay-in with DH and relax, but since they made the trip, we went out.
To be fair to the situation, I should probably state that I was a little less-conversational that I usually am (as I was tired), but I did contribute to the conversation and was as cordial as I could be. Turns out, MIL was put-off by my "attitude" and called DH a few days later to complain about me. She told him how rude I was at dinner, and how she felt like I didn't want them around. MIL tells DH that I need to fix my attitude.
Thankfully, DH tells me about this conversation, as I feel like I have the right to know. I haven't broached the subject with MIL since, but it has been difficult for me to forget. With both of these events, I feel like I was unjustly accused of being rude, and I'd like to say something to MIL to clear the air. Do you guys have any advice on whether I should mention how I feel - if not, I feel like the awkwardness could linger on. What should I do / say?