'I suspect my GF of 4 years is cheating on me with our roommate.' UPDATED

"Me [23M] with my girlfriend [22F] of 4 years, I think she is cheating on my with our roommate."

My girlfriend and I have always had a lot of fun together, she is my best friend and the absolute love of my life. I planned to propose this Christmas, already have her fathers blessing.

Recently I noticed her acting differently with our roommate, who is also one of my oldest friends. He's known for being a womanizer, always has different girls leaving in the same clothes they had the night before.

I came home from work and they were quietly whispering in the kitchen, it sounded like a serious discussion, and when the door closed I swear I heard her say 'Shh! He's home' and when I walked into the room they shot apart.

It could have been paranoia on my part I guess, but then last night when we were all sat watching some stupid reality show that she loves, she was on her phone the entire time. His phoned buzzed and I saw her name on his screen. They were texting while we were all in the same room. That can't be good can it?

How do I bring this up? Do i confront her? Him? Do i need to sneak for evidence?

tl;dr: Girlfriend and roommate were texting while in the same room. Tried to deny it and hide it from me. I smell a rat.

This is what people had to say to OP:

inspctrgdgt said:

Really? Your mind jumped to cheating? 'Cause mine jumped to "Christmas surprise"...

mr_shush said:

You've got some circumstantial evidence here. It certainly could be bad, but it could also be nothing. Christmas is coming up - maybe she's working on a surprise gift for you? Talk to her. A ruined surprise is a small price to pay for preserving what sounds like a good relationship.

SasZ79 said:

Put a Voice Activated Recorder in your Home wait a couple of days and then look for the evidence. Good Luck.

And [deleted] said:

The fact they shot apart when you walked into the room and are texting when you are right there would indicate to me this isn't some kind of nice surprise. I'd sneak into your gfs phone for sure - confronting them won't do anything.

Two days later, OP shared this update:

Thank you to anyone who replied with advice, etc. I really appreciate it. As one commenter rightly guessed, I have been cheated on before. It was one of those, after I found out and ended it, it turns out some of my friends had noticed and never bothered to tell me. So now i worry I look for the signs a bit too much. She's never give me a reason not to trust her, until this whole roommate thing came about.

I'd like to clear up a few points: When he first moved in, she didn't approve of his 'promiscuous ways', she was worried about lots of different girls having access to our home when we're not there, and while she made her feelings clear, they still remained civil.

Stayed out of each others way, small talk, etc. He told her his only rule for sleeping around is that everyone involved had to be single. He's a strong believer of 'bro code', which makes this harder to swallow for me.

She has never made me feel the need to snoop, she charges her phone on my nightstand, instead of her own because hers is full of books and a lamp. if she had something to hide, she wouldn't leave her stuff so out in the open would she?

After the other night, she left her phone on my nightstand as usual and pretty much went straight to sleep. I admit, I tried to look. her password had changed, which shocked me a lot. she only has a password to stop from butt-dialing people. everyone knew her password, she's a very open book about stuff.

I got so angry I couldn't sleep, this is another red flag right? But I couldn't exactly wake her and demand her new password could I? without giving it all away. I fumed for ages, got about two hours sleep.

Last night is where everything went wrong. She messaged me, saying she was on her way home and she'd meet me there, did I want anything specific for tea? I said steak, she said can you pick up this and this from the store on your way home, I said yes, see you later. Still angry and hurt over my failed snooping attempt the night before.

I get to the store after work, knowing she was home, and when I went to pick up what she had asked for, they had ran out. So I decide to ring her to see if there was any alternative, or to just leave it. There was no answer. I rang again, no answer. My stomach was in knots at this point. I ring my roommate, no answer. stomach doing backflips. I rang the house phone.

No answer, so something in me snapped and I rang over and over, let it constantly ring until one of them picked up. She eventually answers, sounding out of breath, [another red flag to me]. I was so angry at this point i snapped at her saying where the hell have you been? she claims to have been in the shower.

I ask where the hell is he? she claims to not know, the house was empty when she got home. I don't believe her, and say I'll be home in twenty.

I gave her an incorrect time, so if they were up to something I'd catch them in the act. I was home within five, and when I got there she had got back into the shower. He wasn't home. Her phone was on the table, so I guessed her password again and again until I disabled her phone. I was so angry I didn't even care. I banged on the bathroom door and told her to get out, we need to talk.

She came out, wrapped in a towel, eyes worried. I demanded to know what was going on. She said she had no idea what I was on about. I told her to unlock her phone, because I know they are up to something. She started to get upset and begged me not to do this. She said I was ruining everything.

Sounded like an admission to me, so I called her the s-word and said if she didn't show me her phone right now, I was leaving. She started crying, unlocked her phone and threw it at me, then went to our bedroom and shut the door. Instead of following, I started reading.

Well, half of you were right. It was a Christmas surprise. Our roommate works at a sports shop, she had arranged for me to get a whole new football kit, not just for me, but for my entire sunday league team. She had been asking the guys their sizes, and messaging them to my roommate so he can keep them to one side for her at the store.

I felt so sick, this amazing girl has been trying to do something for me that I really needed. I'm captain of the sunday league team and I'd been moaning about the cost of a new kit, so she's using her own money to do this for me. And I've just called her a horrible word and accused her of sleeping with our roommate.

I heard her crying from our bedroom, so I knocked on and started apologizing. Screw it, I even got upset and started crying. I can't believe i caused this. she wouldn't answer the door, kept telling me to eff off. then she used the phone in our room to ring her dad, he came for her, asked no questions on why she was upset, just gave me the look that makes my ass leak.

She packed a bag, and she's gone back to her parents place. I broke down and confessed I 'd been planning on proposing, I don't know what I expected it to do, but she got really angry and told me after four years together, if I can jump to an extreme conclusion so quickly then I'm not ready to be married, I don't know her at all, I clearly don't trust her, and there is no hope for us.

I've been blowing up her phone since, until she either blocked me or turned it off. I let my anger get the best of me and now I've lost the best thing that ever happened to me. She told my roommate too and he came home pissed at me as well, he said he can't believe I think he would do that to me. She left me, roommate is pissed at me. Safe to say I've ruined Christmas and lost my incredible girl.

Any advice how to fix this? I don't want it to end over something so messed up on my part.

tl;dr: Girlfriend wasn't cheating, I called her a bad word, she left me. Christmas is ruined.