No hun, it doesn't mean he's cheating! If he was having more sex, his endurance would only go up! It's not a sign of cheating at all, and it's not "your fault" so please don't worry.
Lots of things can cause it, like general stress, is he dealing with something stressful in his life right now? He is most likely just as worried as you are.
Or have you changed anything up in the bedroom? Maybe he's simply getting too excited because you are doing something new! Maybe he is suddenly self conscious about himself. It can also be due to diet changes, and many other completely normal things.
Hi worry, I see you are very concerned with your boyfriend ejaculating too too quickly...
Before, he could go a long time (what you're stating).... Was this with a condom or no condom? And now, he's ejaculating too fast... Is this with a condom or no condom?
I will help you get down to the root of his problem...
Please respond...