i dont play this high and im still pretty fishy at my micro limits but ive watched lossefer alot playing against a friend of mine and this almost positively the flush for him QQ

hmmm
I don't like the River bet actually, given the lack of history/dynamic. Even though last time I checked/played with him loosefer/rnbsalsa was an uncreative supernit post-Flop, I know he has been getting coached by a super-sick player recently (maybe not anymore though) and this River is a great spot for him to have a well-balanced range of thin-ish valuebets, 'standard' valuebets and bluffs. In my experience I have no reason to have to credit him with basically being good enough to have said well-balanced range but given your overall line up 'til the River, check/call as a standard seems best to me... he could valuebet worse and almost definitely bets all his bluffs.

the artist formerly known as sOah

Agree with simon about c/c river, unless you are superconfident in that you can either bet/fold or bet/call. I also think loosefer is a nit postflop and I wouldnt give him credit for bluffing here enough.

I have played loosefer A TON heads up, unfortunately, he refuses to play me now :(

I would bet my life that a check/call here on river is smarter than a front bet for reasons obvious or already stated.