The more I think about this the more I like it...I'm feeling devilish tonight!
Here's the scenario, you have gf call or return a call to her while H is around. You ask while still on the phone with her if he wants to go out, free bbsitting! tomorrow night?
If he waffles or says no...chat with gf about YOU and she going out instead...say to H (while gf is still on the phone)..gf wants me to go to the movies/dinner, if you're not up for it...