i dunno this guy or y'all's situation other than what i've read.

the story in the OP reminds me of situations i've been in - and i've been on both sides of this issue. in my experience the party who wants the romantic relationship doesn't get over that desire for romance. and if they agree to be a friend the agreement is premised on their lingering desire for a romantic relationship. their 'friendship' isn't true friendship - they're acting as a 'friend' hoping that the uninterested party will change their mind about the romance. in the interest of changing the uninterested's mind this 'friend' will attempt to be The Perfect Friend. they won't actually be themselves. meanwhile the uninterested party is getting everything s/he wants from the 'friendship' and the interested party gets mostly consternation. the real test of the friendship comes when the uninterested party develops a romantic interest in someone other than the 'friend'. in my experience, the 'friend' is crushed by this development - but a true friend wouldn't be crushed if their friend starts seeing someone romantically. that right there tells the truth behind the lie - the 2 parties weren't actually friends at all.

but i digress...you don't have to bone this guy to be a good friend. in fact i think boning him would be the worst thing you could do to him considering your knowledge of his feelings. i dunno the guy and maybe he's not like me or the guys i've experienced this with. maybe y'all are different.

from the outside continuing w/the friendship seems selfish on your part and foolish on his.