I’m not sure how I’m supposed to feel when my boyfriend (M 22) of 4 years caught feelings for another girl (F 21) while with me (F 19)

I guess I’m just desperate for advice or just opinions on this..

so I’ve been in a LDR (TX to CA) with this guy for the past 4 years.. we have had problems over the years but despite that I’ve always kept my faith in us and loved him unconditionally.

Even though we’re long distant I visit him every other month for roughly 2 weeks, and recently I went to visit him (for a month). One day when he was asleep I guess I just got a weird feeling and looked through his phone out of curiosity.

I found on his Snapchat that he was talking to this girl for about a year that he met on League of Legends and he never told me about her. Apparently he ended his friendship with her because he had feelings for her (message was not saved) but I just saw where he said good bye to her, which was about 3 months earlier.

Honestly I’m quite devastated that he hid her from me for a year and developed feelings for her.

When I confronted him about it he seemed genuinely sorry about it and said that he was confused at the time because of our issues and ended it with her because he knew he wanted me.

Later I found out via a close friend of ours that she had a boyfriend the whole time. So now I’m wondering if maybe that was the reason he ended their friendship..

Either way I’m pretty lost and would just like some feedback. I don’t know if I should be proud that he stayed loyal and didn’t cheat on me with her (she lived near him) or if I should be upset because he lied for a year about her, developed feelings for her and had our friend lie to me too and was never going to tell me about it.. I’ve never made a reddit post so here goes nothing.

TL;DR My boyfriend had feelings for this girl while with me, and lied about her for a year. I just need feedback