How would you respond?

I had texted my best friend to see if she wanted to do something for the 4th(was thinking of getting my boyfriend and his friends together). Told her my boyfriend was possibly working that day.

She said she’d look to see what’s going on. mentioned a party at a bar. Today she texted me “I’m going to (good friend’s) beach house for the 4th if you wanna come” I had asked if she planned on going home that night because I had work the next day, which she is. Her last text goes “I’m leaving at 9 am to beat traffic if you wanna come”

Now my boyfriends not working and since his family is all away for the 4th I don’t wanna leave him alone on a holiday because that would suck.

All of my friends since high school are going and ones bringing his S/O.

I don’t know how to respond. Do I just tell her I can’t make it because boyfriends not working and I don’t want him to spend the 4th alone?