Что поставить " to ask" либо "asking": How can you forget

 How can you forget asking me out to dinner? Heres the email you sent me. We used asking to indicate that the action did actually happened but the doer of the action doesnt remember about it. If you want to indicate the fact that the protagonist actually forgot to do something (which was necessary), you must use an infinitive with the particle to after forget. Example: My telephone is dead, I forgot to charge the battery last night. Unfortunately, I forgot to book a table for tomorrow, I hope we will be lucky to get a place.