This can happen to men, sometimes age-related, sometimes not. It's a problem in the mind, since the mechanics all work fine, but it's often hard or not possible to determine what triggers it. This issue crops up quite often in the Mens Health forum. It can happen without being anything whatsoever to do with whether the man still finds his partner attractive, or is turned on by her. The most difficult thing is that it becomes a self-fulfilling prophecy - the man worries about losing his hard-on, but worring and stress is exactly what can cause him to lose it.
If you make a big deal about it with him, it's likely to stress him out more about it, and that will make the problem worse. If he starts to lose it during intercourse, manual stimulation may help to recover it, either given by you or him. If you do that, try to make it just part of the sex play, rather than "something you are doing to get him hard again". Also the chances are better if you catch it early, rather than once it's almost completely soft.
My guess is that the shutting his eyes and turning his head is because he is trying to use mental stimulation to try and stay hard.
Communication is the best resource...you'd be surprised in how we analize their thoughts and feelings the wrong way...
u gotta **** more gals...lesbians r better coz u get two in 1 time...**** n lick their *****