<human>: Can you provide a brief rundown of the text in within 3 sentences?

So, yesterday was my mom's birthday. And I forgot it. Her birthday is quite possibly the easiest birthday to remember, as it is literally the day after mine. But I forgot it anyways. Not only that, but she even called me that night (sounding slightly intoxicated) asking me something about money, and I still didn't remember to say Happy Birthday. 

But that, of course, is not how I fucked up.

This morning, realizing my shitty mistake, I decided to call her to apologize and say happy belated. I had stayed the night at my girlfriend's the night before, and we were getting ready for the day when I decided to call. So I pick up my phone, dial, and hear it ringing. It rings a few times, and I say to my girlfriend, "yaknow, I don't think she's going to pick up." "Why not?" She asks. "Last night when she called she seemed kinda drunk." I pause. I realize the ringing has stopped. I stammer "...Hello?" and am received with "oh hi [my name]". I stutter out an apology for forgetting her birthday and she thanks me. Then, she informs me that she did hear what I just said about her before. I try to apologize once more, and blurt out something like "I was just explaining to my gf that I didn't think you'd be awake this early because last night you didn't seem entirely conscious" which was probably NOT the right thing to say. 

My mother, I should mention, is a devout Christian. Doesn't believe that a man and a woman should even share a bed before marriage.  So not only did I call her drunk, but in my defense I revealed that I was staying over at my girlfriend's well before marriage. She didn't condemn me, just mentioned that she understood what it must mean for me to be there so early, probably assuming I already know her feelings on the topic and judging me with her tone of voice. 

So
<bot>: I forgot my mom's birthday, and to apologize I called her a drunk and told her I'm sleeping with my girlfriend before marriage.