Why He's Not Asking

I believe I know why M hasn't asked me to marry him yet: His parents don't like me.
There have been subtle clues throughout the years.

• They think slutty me took their son's virginity and ruined his Catholic purity. Nope, he was ruined before I got to him.
• When we broke up for 48 hours, M's dad heard him talking to me on the phone and said "You're still talking to THAT girl?" and then stomped away pissed. I heard it in the background. This was after we'd been together for a year.
• When I moved to Maryland, his dad wouldn't let him borrow a car to help me move because it was a waste of mileage for someone M was just going to break up with. Because I was bound to cheat on him as soon as I moved away. Seriously, M nearly went crazy on him for saying this.
• I would always go on vacation to see family and M would come with me. We have been to DC, North Carolina, California, and Texas - all places where I have parents who we've stayed with to save money or got a free trip from a TV show. Apparently this was me being "spoiled" - exact description of me. 

And I know M still cares a lot about what they think of me. When I bought us tickets to Disney for our third year anniversary, he didn't tell them until two weeks before the trip. He was worried they would think of me as being spoiled again! When we got asked to be on Jeff Probst show and be flown to California for a day - he still hasn't told them about it because he's embarrassed. Why? They interviewed us about our long distance relationship, we weren't some Maury freak act!
It hurts in a way to know that after 3 years together, he still doesn't have the guts to stand up against what they think.  I'm no undesirable woman version of Beau Hunk.
1) I am not ugly or smelly or repulsive
2) I ran a marathon and passed the CPA in the time that they've known me
3) I have a job that pays well in a very stable industry
4) I'm getting my masters
5) I have always paid for M at restaurants, bars, vacations - you name it
6) I have texted them on their birthdays
7) I have always acted excited about their gifts (hand sanitizer and extra extra small sweaters)
8) I have always bought them gifts
9) I haven't gotten knocked up by their son
10) I haven't unleashed my crazy teenage drama side
I have a lot of factors against me:
1) I'm not Catholic or even Christian (but I've attended two masses with them and behaved)
2) I come from a pretty broken up family
3) I make more money than his dad does
4) I drink a lot (their son drinks more)
5) I've been to Europe
Um, that's it. Where's my damn ring?