I (32M) declined sex with my (33F) wife

Last night, my wife tried to initiate sex, something which she rarely does. I was quite tired and declined but suggested we snuggle. She agreed but wanted to finish using her vibrator first and asked me to help. I again declined and moved off to my side of the bed until she was done. I also commented that she regularly turns me down and it’s not a big deal. This was taken as a serious offense, especially since I had turned her down the night before (that time I was actually asleep when she initiated). How could I have handled this situation better?

Update: Thank you all for your responses, this got way bigger than we were expecting! A couple things:

1. We’ve basically agreed that the primary issue was the comment and associated feelings around “score keeping” etc.

2. Yes, we have some communication issues we need to work on, however this seems to be one of those rare times that Reddit actually helped open the dialogue, so thank you

3. Any variation of “flip the genders and…” yeah, we all know what would happen if the F was where the M is. Those comments don’t help; we’re real people and don’t need to add hypotheticals to the situation

4. I’m off to fuck my wife now, goodnight ?

Update 2: I think my one additional comment after posting this may have been misleading. I did not decline participation out of resentment or score keeping, it was genuinely because I was tired (and am on a bunch of antibiotics which have me feeling off). That said, the comment itself did at least partially come from a general sense of “well you do this all the time” which is something I need to work on.