Unknowingly slept with girlfriends sister

Anon or delete please.

So I am 20 m, and I have been going out with this girl for about 6 months ish she's 18. To make this easy I'll just give them names.
My Gf =serena
Other girl= Becca

So yeah me and Serena have been going out for a while but about two weeks ago she kind of cooled things off with me and so we kept our distance. And so I was doing my own thing and then about a week after I went to a club it was a 20th birthday of one my friends so I went to this club where all of then were going. So I was talking to Becca, who was pretty seemed nice etc. (first time I had met her), so I got to know her etc. Note at this point I thought that Serena had broken up with me. So yeah Becca told me she was 20 (my age) and we got talking and all that. After a while the club started getting hot and loud. So I asked her if she wanted to go to my place (flat). And that night I had sex with her...

It was my first time and I didnt think it was becca's first time as she seemed to know what she was doing well enough. So anyway it was good and I immediately regretted it as it didn't feel right, you know. So after the night I hadnt spoke to serena for the next couple of days. And so I started texting her. After that night I hadn't talked to Becca since then. So I felt guilting not telling Serena that I had had sex, but I thought we weren't going out together, so I didn't really see a reason to tell her. After that day when I had met Becca(a week later), Serena texted me saying to come over to her house.

So I went over to her house and I was anxious at first but nevertheless I went in. So Serena led me to her room, (I'd been in there before but this was different). As when I had knocked on the door she started hugging me and then full on kisses me. I was surprised and then she stated apologising saying that shed been busy with stuff and just saying she was sorry er. At this time I became incredibly uneasy. Anyway she took my hand and began leading me to her room. Her parents weren't in btw. So as I was in her room, she was saying how her sisters were going to come later to her house. Anyway she had lit her tom with candles and it was clean and smelled nice.

Anyway she started taking her clothes off and I could see where this was going . Anyway I felt really uneasy with what had happened with Becca. So anyway I told her that I needed to tell her something but she told me to tell her later. Anyway she was undoing the buttons of my shirt off and I was getting really uneasy. Then Serena had nearly took my clothes off and so we were making out and she was on top of me and then I got an erection. Anyway I still had my boxers on at this point.. So she told me she wanted to have sex and I the. Decided i needed to tell her. Anyways she wouldnt listen and started pulling my hair and that. And then her phone rang and she was saying to leave at she really wanted to do this (have sex).

And then I saw it. When her phone rang it came up with the caller Becca. So I said to Serena, who Becca was (note that this isn't their real names) and then she told me it was her sister and then I saw that under the caller if there was a picture of Serena with Becca. And then I had realised that Becca, the girl who i had lost my virginity too was Serenas sister. So I made this realisation whilst me and Serena were both nearly baked and then I told her that I had to go.

Serena was then starting to get upset and it really killed off my erection and I felt like crap. I think that she thought that I just didn't want to have sex with her - which wasn't the case. Anyway I started putting my clothes on and so did Serena and she looked like she was going to cry

And so then I started walking downstairs to go to my flat. And then the doorbell rang and it was Serenas whole family including Becca..
So as I was trying to leave, her mother forcibly told me to eat dinner with them. So I couldn't go and ended up there staying. So there I was eating dinner with Serena on the verge of tears which was killing me inside as she if self conscious and that. But the worst was Becca. She kept giving me these flirty looks and started hugging me not telling the others that I had had sex with her after we had ate.

Anyway after I just wanted to get the hell out of there. And so as I was saying bye, to Serenas family, Becca said she would walk me out which was the last thing I wanted. And as I was leaving, Becca pushed me to the door and told me not to say anything to Serena about what had happened. So at this point she had understood that I was Serenas boyfriend. And then she jammed her tongue in my mouth and then pushed memoir of the door.

And then I just started crying about how I had sex with this b1tch and how I had made Serena so upset and about how I was going to have sex with my true love and girlfriend and how I just felt like a great big bag of d1cks.

So now I don't know what to do as Serena won't believe me if I tell her the truth and Becca will make my life hell etc, I lost my virginity to my girlfriends sister, if my Gf does believe me she will never forgive me and I love Serena.

Note - her sister had finished her semester and was visiting Serena and her family .

Sorry for errors, I am on my phone.

Thanks

Sorry just minor corrections on phone so don't know how to change it

Don't worry about it - your post was pretty coherent (especially for someone typing at length on their phone!). I don't think you can "edit" anonymous posts anyway since they're not tied to your account in the same way that normal, non-anonymous posts are.

You probably won't get many replies at this time of night, but hopefully your thread will get a little more attention in the morning.

Tell your Girl friend what happened and then I think the best thing to do is not see her anymore and understand that it IS your fault. After that try and be a better person and move on with your life.

This sounds suspiciously like a thread I read the other day with characters 's' and 'b'

Sounds like a story for Jeremy

I read that thread. That was from gossip girl, this is real life..

Confess to your girlfriend about what happened, she needs to know also if her own sister is trying to still get it on with you knowing that you are her sister bf, then that is really some shady behavior and your girlfriend needs to be informed about what kind of person her sister is

Yeah I'm sure that I should tell her, it's just the backlash that I'm worried about..

Its likely that you two will split up and man never assume anything, you should have just asked her what was going on instead of thinking that you weren't together, tbh this all could have been avoided

x