Sorry to hear about this.
It sounds like he might be suffering from "Frontal Lobe" dysfunction, most likely from all the strokes. This causes people to be disinhibited and inappropriate
in social settings.
I would first start by having him evaluated by a Neurologist and getting an MRI of the brain. A Neuropsychologist may also be helpful in sorting out if there is a dementia co-existing that can be treated with medications.
For symptoms such as this, I commonly prescribe extended release valproic acid once a day. It is used as a "mood stabilizer" and often deals with the problem in a healthier way then would be accomplished with the use of "anti-psychotic" medications. Please ask your doctor/Neurologist about the use of this medicine, or others like it, to help regain some control of his behavior.