I'm sorry to disappoint you but.......
Could you say "Lo siento a decepcionarte pero......."
best I can see is that it's "lo siento por decepcionarte" which carries with it not entirely the same meaning. "I am sorry for disappointing".
I'm sorry to disappoint you but I am married already! I'm sorry to disappoint you but I ate all the gravy once again just like I always do, and you didn't get any! I'm sorry to disappoint you but I am not your father. I'm sorry to disappoint you but I don't run fast. I'm sorry to disappoint you but you aren't getting into my car. I'm sorry to disappoint you but we could only get it up to 87 miles per hour....now we have no way to get home.
Lamento decepcionarte, lo siento por decepcionarte....... but these don't seem figurative, like "Sorry to disappoint you bud, but you better not think you're getting the last donut".
4 Answers
You could just use: "Siento haberte decepcionado, pero..." (although it's slightly different, literally, "Sorry to have disappointed you, but..") or you could use: Lo siento que te tenga que decepcionar, pero...". (although that seems a little wordy, and literally means, "I'm sorry to have to disappoint you, but..."). Alternatively you could say: "Lamento decepcionarte, pero..." (which essentially means, "I'm sorry to disappoint you, but...").
At wordreference I also see lamento deceptionarte..., but I wonder if that carries the true meaning behind the English, which is more like I'm afraid/I'm sorry I must disappoint you.
I would've guessed something more like Me temo/Lamento/Siento que debo decepcionarte, pero...
Of course, it's all about patterns. Whatever Spanish speakers say for this is whatever they say, right?
I think it is important, too, that the phrase can be sincere, but more frequently the English phrase is used sarcastically...it's almost like sticking your tongue out at them as you quickly grab that last doughnut, but more friendly...you are usually smiling at them.
You could also say: Lo siento por desilusionarte.
Weddunce does have a very good point about sarcasm. It very often does not work well at all in Spanish.
Just a final check. So desilusionar is a synonym of decepcionar, and siento haberte.... can mean sorry to have....... even without the lo to mean sorry.
- Siento haberte decepcionado, pero - sorry to have disappointed you but....
- Lo siento que te tenga que decepcionar, pero - I'm sorry that I have to disappoint you, but.....
- Siento desilusionarte - Sorry to disappoint you.
Siento can be used without LO then? Siento perderte = I'm sorry to lose you? Like when someone leaves? Gracias.