That's not romantic, that's nutty.
Marcus has given us NO indication that he feels anything but friendship, while Charlie has been the one squealing, "I LOVE Marcus!" Pathetic and one sided. And even then, have you ever heard Charlie once say, "I think Marcus might feel the same way about me?" No. Because even he's not that deluded.
Also, did it occur to any of you that Marcus has a vested interest in being affectionate towards Charlie? If I realized some desperate, clingy guy was mortgaging his entire game just to win my favor, um YEAH I'd be nice to him. Marcus can use Charlie (which is OK in the context of a game) to get closer to the grand prize. He's not stupid, and he's given us no indication that he's playing Survivor for anything other than money. Charlie is the only one who seems to have forgotten the game objective and is potentially playing for Marcus, not for himself.
Don't mistake Marcus' game moves for latent homosexual desire. If you do, you're misreading things as badly as Charlie is. Actually, since Charlie doesn't seem to think Marcus is harboring romantic feelings for him, that would make your misreading even worse than Charlie's.