That is, romantic threesomes that last more than a night/weekend. Any ages, any combination of sexes/genders, any level of commitment.
I know about aroslav's "Not This Time," tendertouch's "Protective Coloration," and one by Argon, I think it's "Suddenly Rich Kid." Any others? (Don't bother to rec my stories, of course.)
TIA
ETA: Specifically threesomes, not moresomes, thx.