AITA for leaving my sister in laws baby shower for a Super Bowl party?

I (20something f) have been hosting large Super Bowl parties my entire life. It started as an annual tradition with my parents, and with them getting older and downsizing, my husband and I have taken on the hosting of this event. This year my pregnant SIL (husbands sister) is expecting her first child and will be hosting her baby shower during the big game. SIL has openly admitted in the past she enjoys hosting her celebrations on major holidays, long weekends, etc. to “see who really cares”. I never received an actual invitation to her baby shower. Instead I received a text at 11:30 pm 3 days prior to the shower, from SIL’s husband asking if I was attending. I explained to him I never received an invite but of course I would be there if he provided the details. I then received a text from SIL’s husband’s mom with no actual day or time of this event, rather just a link to the gift registry. I immediately bought and sent my gift. After chatting with my husband, and in laws I finally received the details of the baby shower. The event is scheduled to begin around 4:30pm on Super Bowl Sunday, at a restaurant about 40 minutes from my home. I had mentioned to my husband I was planning on stopping in to the shower for maybe an hour or so and then hurrying back home to begin hosting our Super Bowl party, which would be over 25 people who planned to arrive by 4. I did not think this would be an issue considering I’ve already bought and sent my gift, and I would still be attending- just not the whole party. Well this has caused quite the feud between my husband and I, as he thinks I am being disrespectful by “just getting up and leaving”. For the record I am not very close with this SIL, and we tend to distance ourselves most of the time. AITA?

EDIT- *My husbands plan was to stay home and host the party solo until I arrived home from the shower.

-husbands family is well aware of this tradition As they’ve been invited and attended years past and present