As I siad above, very few men will propose just because their girlfriend “throws a fit”. If they do then it’s their problem for not man-ing up and ending the relationship if that’s what they want.
Lots of women make strong hints at engagement after they’ve been dating for a while.
When I was dating my wife, I encouraged it because I already had cash on a ring. I kept telling her I was saving for an expensive kayak as she wondered where my money was going.
Actually I had great fun with that story. She was super surprised when proposal day came though.
The OP is not privy to the intimate details of this relationship and really she doesn’t have the information to make a call on whether or not she should “object” to this marriage.