More than you could ever realise
As is always the case when she is on a date, you will have trouble at home doing anything except thinking about what she and her boyfriend are doing -- although you know that she will not be spending a moment during that time thinking about you. Such is the life of a beta cuckold. It's not the life you chose to lead, but you have accepted that it's the only life that you are suited to be able to lead -- a point your wife makes clear to you quite frequently.
[based roughly on a MsTara original ]