<human>: Can you summarize the given text in a few sentences?

My boyfriend Alex and I have been dating for 2.5 years, living together 1.5 years. We've been best friends since our junior year of high school.

I have a tendency to be really sarcastic and blunt. I also think that everyone understands that 95% of the time I am joking and never assume that someone takes me seriously. Alex has always been perfectly fine with this and never takes anything I say to heart.

The last few days, I've noticed that Alex has been really sensitive. He doesn't laugh as much when I say things and takes a lot of things I say as criticism (even though I don't mean it that way). Everything came together this morning when I harped on a joke about something minor he did for about 15 minutes, and then he started crying. He told me he felt really attacked and just wanted me to stop talking.

I was completely shocked that he had this reaction, as I thought he wasn't taking me seriously and it was understood that I was joking. I apologized immediately and he said it was fine, but I still feel like an asshole. I've realized I really do sound like a critical, negative douchebag all the time.

Reddit, how can I stop doing things like this? I need to know how to speak more sincerely and stop defaulting everything to jokes, because it's becoming very clear to me that they aren't jokes and they're hurting someone I love. I need to know how to talk to Alex about things he does without it seeming like criticism. I never want to do something like that to him again.
<bot>: My sense of humor is that of a critical asshole, made boyfriend cry with it, need to know how to stop speaking like a critical asshole.