secondly how to politely say noto socializing with out disrupting the business relationship?

I base that on the long term Case Shiller data that, after adjusting for inflation, shows house prices are flat, except for major disruptions (great depression, loosing of lending after WWII, and the recent bubble.)

Aside from giving you migraines it ties you up legally and brings major disruption to what you are trying to do. 

Your only concern is the behavior which is disrupted to other tenants/neighbors and not in keeping with the legal mandate that tenants have the right to the peaceful use of the property. 

I am not suggesting you can do this with any and every tenant, but when you have someone who has paid on time for a substantial amount of time and then something happens to disrupt this, I would say that it is not a good idea to push them away as a first response.   

A high maintenance client can really disrupt your life and make you less productive -- especially if real estate is something you do on the side. 

Prices go up because of government restrictions, lockdowns, regulations, Disrupting Supply chains causing prices to increase 2.

He has no obligation to adapt to your change in circumstances and every obligation not to disrupt his daughters life/time with him. 

It doesn't seem like it will disrupt the flow in any meaningful way between them.

This way you can comply with their request and not disrupt your quarantine.