Most Helpful Girl
It doesn't really make me think less of the guy. It depends on the guy and the type of "vibe" I get from him but I would probably think 1 of 2 things.
The more likely thing I would think is:
"Wow she must be rich/she must be f*cking him really well", especially if she's MUCH less attractive
If she's a little bit less attractive I'm more likely to think that he probably just likes her a lot. But honestly, it is unusual to see an attractive guy with an unattractive girl, since guys are more looks-oriented. I mean, if you see a young girl with a much older unattractive man, you know it's very likely that he has money and he's getting a nice roll in the sack for it.