I loathe my ILs, this is well documented!, and FIL and I barely speak. However, he drinks and drives and I feel compelled to make shitty comments which leads to a horrid atmosphere.
All I want DH to do, when FIL requests another beer/glass of wine, is to say 'No Dad, you're driving'. If he gets moody I couldn't give a crap, tbh. I hate drink drivers.
He's on his second can of Stella which is 2.2 units.