Special CEI time with girlfriend

Coming back from work, you find your girlfriend very keen to help you cum. Especially since you've been continually sending her texts and pics all day long, asking for nudes and telling her how badly you want to jerk off but cannot just yet. Now that work is done, it is done to have some fun, but your girlfriend seems to have some rulea about how you're going to play today: you jerk off to her teasing you, then you cum in a shot glass, pour it into your mouth and instead of swallowing right away, just hold it in for as long as she pleases. It's either that or you don't get to cum today, so what's it gonna be?