Yes, it is VERY rude and disrespectful.

I mean - we are guys, afterall. So we will look from time to time. But the way you describe his actions is just unacceptable. He's going way beyond "from time to time" and it's creating a lot of problems for you guys. If he loved you so much - why can't he do somethin so simple as to not GAWKE at the girls walking by.. it's not THAT hard to do, honestly.