Welcome to HCM.
Increased sweating is an inherited activity for some people. Sweating is very useful in excretion of body wastes and also for maintaining the electrolytes,fluids and temperature of our body.
Night sweating is common with tuberculosis
. As your boy friend is otherwise alright you need not worry about Tuberculosis. It is not a specific symptom for HIV.
There are medicines to reduce sweating. But this will stop sweating only when he is on drug. It not only reduces sweating but it will also reduce other secretions like saliva and digestive juices etc.
So it will have unwanted side effects. Use of talcum powder and antiseptic soaps will reduce the odor.
If he has high risk behavior for HIV, there is nothing wrong to have a HIV test
Nothing to worry.