<human>: So I'm 25 and I'm seeing an 18 year old girl.  It's an LDR with about 5 hours in between.  It's been going on just short of a year, 2 visits or so per month.  We're both quite serious about one another.  I'm slated to go to grad school next year at a university about an hour away from her.

Problem is, I'm still a secret.  Despite me being a what most parents would consider a pretty good boyfriend (treats her right, makes her happy, getting a PhD in physics, etc.), my girlfriend is afraid her mom will freak out when she hears about my age, especially considering we started seeing each other while she was still 17. 

So, all this time, she's had to sneak around whenever I've come to visit or she's come to me.  She lives on campus, so this is not difficult, but she has to make up some elaborate stories sometimes over the phone.  Now it turns out that a new year's visit likely won't pan out because she can't figure out what to tell her parents.  Which sucks.

She's worried her mom will think that I just want her for sex, or that she's a gold digger, or (most legitimately) that there just couldn't be anything we have in common.  My explanation for this is that she's a little precocious (been going to college since she was 15) and I started college late, so despite our ages we're in the same phase of life.

The main problem is that my girlfriend's parents still pay for her college, and like to hold that over her head.  She's afraid that her mom will threaten to pull the funds unless we break up.  But, I hate sneaking around, especially when it means I can't see my girlfriend for no good reason.  I don't want to have to fly under the radar anymore.

Give me a shortened version of the text
<bot>: Been dating a girl 7 years younger than me for a year.  Advice on breaking the news to her controlling, authoritarian parents?