Down, Up, Down

Well, Saturday I got to practice some of my new techniques. I was chatting on FB with my sister & she was clearly "baiting" me. But I didn't take the bait! I cooly answered any questions that needed to be answered. The only reason I didn't end the conversation was selfish: I needed to get these family photgraphs from her so I can scan them!
So Sunday afternoon we got together at Starbucks & had a really, really good & mature conversation there. (I think we do our best talking at Starbucks...I should keep that in mind!)
Sunday night before bed, my husband brings up that: 1-he wants to buy a new car, 2-he doesn't want to get rid of the old one, and 3-he wants to pay for it with our equity line (which is next after the credit card to pay off). The car is $10K.
I really don't want to put another $10K on the equity line, nor can we afford a monthly payment. That'll bring it up to about $40K. (And as if HIS $ will go toward it!!) AND I don't want to pay insurance & taxes on 3 cars.
Well, he definitely can't get the car without me...unless he swipes the equity checkbook to get it. But then he'd have to make the arrangements for insurance, etc. Not sure if he'll do that...
I don't know...I've got to lay down the line. His erratic income is not going to cover this & his spending.