one of my closest friends fucked my ex

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33KB, 500x375px

what do i do about it?
i don't have many friends near where i live, most of them have moved abroad so i've only really got him.

but i was with my girlfriend for 3 years and we broke up in January.

then he went on holiday to finland and she went with and i know that they have been fucking.

what do i do?
my friend knows i'm not over her, i've talked to him about it.

what can i do?

also, they don't know that i know, because the only way i found out was through my flatmate, who is good friends with my ex and i saw his whatsapp convo with him about it when he left his phone in the kitchen (the message just popped up and i saw enough to know...)

what do i do?