Re: Should I be upset??
I don't much see the issue.
The band practices at your place on Monday.
You just said they can't practice at your place on Monday.
So they found an alternative place to practice on Mondays.
Sounds like a pretty clear solution to a problem you presented them with.
If you're going to put your foot down about not practicing on Mondays, you can't be mad that someone else won't practice on another day.
Granted, if the band has goals, everyone should be open to obtaining those goals. But you feeling like Mondays is too much is just as much of a blockade to that goal as anyone's opposition to any other day.
Now, as for the bassist getting bent over you buying a bass, well, he needs to grow up.