Janet Maslin: They use frequent quotations from both Sunset Boulevard and The Talented Mr. Ripley to add a frisson of exploitative seduction to the Tommy-Greg friendship. It goes noticeably unexplored that, after Mr. Wiseau coaxes Mr. Sestero into living with him, he leaves his bedroom door ajar. Mr. Sestero hears him saying Somebodys chicken. He also notices Mr. Wiseaus open contempt for women.
Greg's mother said "no sex, Tommy", and his awkward response was "Well, we all do.", not getting the implication that she was referring to her son.
Tommy's nickname for Greg, "Babyface", comes across as slightly... romantic. Judging by Greg's reaction to the nickname, the implications weren't lost on him.
From the movie
The trailer for the movie is cut in such a way that Johnny's breakdown is being paralleled with Tommy's gradually getting more unhinged in real life. However, should one knows the plot of the film the story chronicles, they'll know that Greg's girlfriend doesn't fit Lisa's position, despite Wiseau talking about Lisa when said girlfriend shows up in the trailer. It seems nonsensical... until one realizes that the one "betraying" him in the trailer seems to be Greg.
Not to mention the juxtaposition of the "Anything for my princess" line followed by a rather serene shot of Greg and Tommy shouting that he's making the movie about a romance Gone Horribly Wrong for him.