My best friends girl friend walked in on me in shower [MF]

So I’m going to try and explain this situation in words the best I can I’m confused about this entire situation! So for the past few days I’ve have been staying with my best friend his (M26) and his girlfriend she’s (F25) and I’m (M25) as my metal heath isn’t the best and I’ve not been doing well at all recently. He offered for me to stay over to have some company and it keeps me busy etc. He has been working this week so far but he finishes around half 1pm Uk time. I’ve spend everyday so far working in his garage on his project car which has kept me well and busy.