Partner lies to me with a straight face multiple times

We’ve been dating for over a year now, we’re in a serious relationship, but my girlfriend has been lying to me multiple times already.

About two months ago, she was messaging a guy and hid it when I looked. I asked who that is? She replied “oh it’s just my cousin, you have nothing to worry about you’re thinking too much” with a tone that I’m somehow a psycho who’s overthinking. About a month later, she slipped that it’s a friend. I brought it up, “wow wow wow, you mean its not your cousin? It’s a friend”. To which she responded “I didn’t wanna make you freak out, cause that “friend” is going through a rough time and he was talking to me about that, I said cousin cause I consider him like a cousin we know each other since we’re kids”.

We spoke and I made it clear that I don’t need her to “protect me”, I want the truth and only the truth, and that we should be honest and not lie to each which she swore she would be honest and truthful from here on out.

Fast forward to this week, it’s a weekday, we were both busy hanging out and catching up with our respective families. She sends me a message telling me that her guy friend (another one), has a rough time and that they were talking via Facebook messenger. I’m like okay, anything else to it? She says no no, that’s it.

She drove back home (she lives alone), then she texts me “I’m going in the shower”. Two seconds later, I see her active on Facebook, I send a message. Get nothing, so I text that I’m going to bed, goodnight (at this point it’s past 10pm). I get a response “Sorry bb, drying my hair 😅”, makes no sense, so I answer “Wanna talk before I head to bed?” and I call through FaceTime, it’s declined. I ask “what’s wrong?”. She responds “Give me a sec babe”. I get a regular phone call, not FaceTime call and I get told something totally different than by text and I get a weird vibe: “I’m ironing my hair and I’m talking to my best friend (girl) from another city”. At this point it was obvious my partner was lying to me and was hiding something. Cause she said “drying my hair” over text and then changed it to “ironing my hair” over the phone.

I said goodnight, bye.

And I starting thinking to myself and decided I would drive to my her house. (Context: we track each other on find my friends at all times, so I decided to disable that). I started driving and then I started getting phone call after phone call from her. She even called my sister to ask where I was and when my sister said I was driving to the her house, she asked my sister how long ago did I leave?

At this point, I got to my partners house, and decided to answer her phone call, I didn’t know my partner called my sister, so I made a voice of someone who just woke up. She replied “you’re such a bad liar, you’re at my place, I see you, I’ve been looking to see when you’d come from the back and the front. I spoke to your sister, she told me you’re coming, come up let me see you”.

I come up, and she acts like there’s nothing, and says “I’m sorry I worried you, but I’m good, I was just busy in the bathroom”. I say “really?”, to which she answers yeah yeah I was just getting ready in the bathroom. At this point I was convinced it was a lie, my gut feeling was strong. I said “bullshit, tell me the freaking truth!! Stop lying!”.

So at this point, I could see in her face that she thought that I knew something, so she tells me “there’s was the guy with whom she was talking to earlier via messenger over at her place and that they were talking cause he wasn’t feeling good”.

I burst out the door and said “we’re done, you had the audacity to lie to me point blank to my face, over the phone, and to my sister”. She started crying and holding on to me, saying she was sorry but that she didn’t wanna worry me, because she knows it’s late and I wouldn’t like that.

She’s been begging me for forgiveness and that she did nothing wrong, that she was simply talking to him and she regrets having invited him over. That she’ll never do it again and that she is

Would you forgive and give her a chance or no, that’s messed up?