Estocavio said:
Well if she did have large breasts then hes just stating the blatantly obvious. And god no, not a male complimenting another female besides his glorious mis... girlfriend! Oh no!
Have you heard of respect? If you're in a relationship, you don't go around flirting with other girls while your girlfriend is right there. At least, not if you want her to stick around.
No, it's definitely not cheating, but I at least see her point. If that was enough to cause a breakup though, they probably had other problems.