I hope you mean ex-boyfriend.

Then why on the earth was he telling you about it?

Because some people are very, very stupid.

In all fairness, it could've been a platonic date with a friend or family member. Still an odd way to announce it though.

Dump him

My girlfriend, Salma Hayek, does that to me, like, all ... the ... time!

You got on accidental YDI. I really didn't mean to click it so if you see that, imagine there's one less. You didn't deserve this.
Unless you're a horrible person... But you'd cancel your plans for your boyfriend so you're probably not.

If it is a date with say his mother or sister, then that is fine - but even then, he should have told you he meant them and not you. BUT if it is anyone else other than a family member, that is unacceptable.

You don't want to be with someone that stupid anyway.

That asshole! You'd better break up with him.

im not sure he fully understands how this relationship thing works.

Soooo this is where you go out with that one "male friend" you have (all women have this friend) and actually give that guy a chance.... I guarantee he wouldn't cheat on you