i thought she was cheating on me

Well I’m at home with my gf and we are having a quiet drink together just after a lovely dinner, she turns to me and says that she needs some more to drink. I go to the fridge but I find we are all out for some strange reason since I bought heaps that morning, I tell her that we are out so she ask's me to go out to the store to get her some more.
While I was out at the closest shop this girl approaches me and starts chatting, she seems very nice and forward but something just didn’t feel right it was like I had met her before. all of a sudden she asked me if I wanted to go out to the car and have a little fun but then thinking of my gf at home I refused instead we chat for a little bit, after about 10min of chatting I tell her that I had to get going.
I get home about 30min after I had left to go to the shops. I walk in the door and find the bottles of drink that I had bought earlier that day open and scattered throughout the living room then next to the couch I notice clothes then closer to the room doorway I see a bra and undies, suddenly out of nowhere I hear giggling and moaning coming from the bedroom, I go storming in there thinking its another guy doing my girl but to my astonishment its a girl. The lights are dimed so I couldn’t make out who the other girls is but they are both naked playing with each other, licking every crevasse while feeling the other person’s body like 2 virgins are doing it for their first time.
My gf hears me standing in the door and sees the shell shocked look on my face.
My girl whispers something in the other girls ear, then the girl gives her another pash the slides of the bed and stands up. I could see her beautiful body with luscious breast and a hairless pussy; she starts to walk over to me and starts to wiggle her hips at the same time. She stops in front of me and I look her up & down, she smiles and slides her hand alongside my face to the back of my head and pulls my face towards her and gives me a kiss.
To my shock it’s her best friend that she and I had the hots for. I look over to my gf and she has this big grin on her face, she gets up and comes over as well. she leans over and give me a kiss then tells me to sit down, I see there is a chair placed in the corner of the room facing the bed with a couple of cans of drink sitting next to it. I sit down next and get myself one of the drinks.
The girls return to the bed and start kissing and playing again, few minutes later they have all the toys out and start really going at it. My gf lays on her back with her legs spread while her friend gets on top of her and starts to kiss her way down her body; she makes it down to her dripping wet pussy and starts to work. I could see the look on my gf's face of enjoyment, within seconds later her back was arched and that look changed and then she squirted all over her friends face. She couldn’t stop shaking from the orgasm that she just had. Her besty moved back up on top of her again then started kiss then all of a sudden my gf rolls her over and pins her down to my enjoyment she really pretty much sticks her tongue down her throat.
She works her way down her friend to repay the favor that she has just been given. She does her best to try and get her off but she just takes longer than her friend. A few minutes later her friend orgasms herself and grabs the back of her head to plant it in her pussy. They both lay there side by side all covered in each others juices.
after a few min they ask me to get them another drink, when I come back I find my gf still naked sitting in the chair I was just in playing with herself so I look over to the bed and find her friend using one of the toys they just had out deep inside her. my gf looks at me and said she is getting ready for you so I strip down naked quicker than I had ever before and make my way over to the bed, her friend see my hard dick then tells me to lay down so she can give me head. After about 10min she gets up and slowly eases herself down onto of me till I couldn’t see nothing more of my hard dick, she rides it hard like it was going out of fashion. I look over to my gf and she has one of our other toys inside her playing, she looks like she is enjoying herself watching her friend on top of me then she notices me look and takes it out of her pussy then starts to lick it.
I pick up her friend and throw her on all fours facing my gf at the end of the bed, I start doing her hard from behind for what would of seemed like an hour then my gf looks at me and nods her head so I pull out of her friends pussy and shoot my load all over her ass and back. My gf comes over quickly after I finished and starts to lick up all my cum off her ass.
Seconds later I was hard again so I grabbed my gf and started to fuck her doggie, while I was doing her like that he friend layed on her back in front of her with her legs spread. My gf quickly moved her tongue onto her clit, once she did that I felt her pussy become so much wetter. We go at it for ages then I grab her hips and throw her on her back, I got myself between her legs and keep going at it hard & fast then her friend straddles her face. I start to make out with her friend while still doing it.
Few minutes later once there is juices everywhere again I cum deep in her pussy.
We all lay on our backs catching our breath covered in each other cum.

So for the rest of night we kept swapping with each other making the other cum.

i later find out it was my gf’s friend that stalled me at the shops so I would take longer