Hello Friend, Good that you are seeking a help. I can understand your suitation. No worries, this problem can be addressed with a fair understanding of his feelings with your cooperation. Many times people can't supress natural urge and desire . As how you can't supress sneeze, cough, hunger or thirsty, similarly sexual feelings also cannot be suppressed. However, nature provides some automatic remedies like periodic night fall for men. Moreover, other bodily conditions like excess heat, or spicy foods, access to internet, environments, friends, alcohol also can increase such desire. In ayurveda, there are few home remedies and food control that can bring down such urge. In parallel, there are ways you can support him to overcome this as I can't share in detail here. Feel free to reach out to me online for further evaluation and recommendation.

Talk to him directly or take help of a marital counselor. Also introspect on why haven't you been able to get physical and help him get a hobby to channelise his energies abit atleast